Plantsbrook School
Q1.
The diagram represents an atom of beryllium.
Use a number from the box to complete each sentence.
4
(a)
7
9
12
The atomic number (proton number) of this atom is
.
(1)
(b)
The mass number of this atom is
.
(1)
(Total 2 marks)
Q2.
The drawing shows a container of a compound called magnesium chloride.
(i)
How many elements are joined together to form magnesium chloride?
....................................................................................................................................
(1)
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Plantsbrook School
(ii)
Magnesium chloride is an ionic compound. What are the names of its ions?
................................................. ions and ................................................. ions
(1)
(iii)
How many negative ions are there in the formula for magnesium chloride?
....................................................................................................................................
(1)
(iv)
Complete the sentence.
Ions are atoms, or groups of atoms, which have lost or gained
......................................... .
(1)
(v)
Suggest three properties which magnesium chloride has because it is an ionic
compound.
Property 1 ...................................................................................................................
....................................................................................................................................
Property 2 ..................................................................................................................
....................................................................................................................................
Property 3 ..................................................................................................................
....................................................................................................................................
(3)
(Total 7 marks)
Q3.
(a) A magnesium atom contains 12 protons (●),12 neutrons (o) and 12 electrons
(x).
Which diagram, A, B or C, represents this magnesium atom?
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Plantsbrook School
This magnesium atom is Diagram
(1)
(b)
Magnesium metal is shaped to make magnesium ribbon.
Tick (
) two reasons which explain why metals can be shaped.
Reason why
Tick (
)
The atoms are all joined by covalent bonds.
The atoms can slide over each other.
The atoms are large.
The atoms are in layers.
(2)
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Plantsbrook School
(c)
Magnesium sulfate is a salt of magnesium.
It can be prepared by the reaction of magnesium metal with an acid. The equation
for the reaction of magnesium with this acid is:
Mg(s)
magnesium
+
(i)
H2SO4(aq)
acid
→
MgSO4(aq)
magnesium sulfate
solution
+
H2(g)
hydrogen
Draw a ring around the name of the acid used in this reaction.
hydrochloric
nitric
sulfuric
(1
(ii)
Use the equation to help you to answer this question.
Tick (
) two things that happen when this reaction takes place.
Tick (
)
Bubbles are produced.
The magnesium disappears.
A solid is formed.
Water is formed.
(2)
(iii)
Draw a ring around a method to get solid magnesium sulfate from magnesium
sulfate solution.
crystallisation
electrolysis
oxidation
(1)
(Total 7 marks)
Q4.
(a)
An atom of aluminium can be represented as shown below.
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Plantsbrook School
In this atom of aluminium the number of protons is ............................. and
the number of neutrons is ...............................
(2)
(b)
Which statement in the table below describes the mass of an electron?
Tick ( ) one box.
Statement
Tick ( )
Electrons have a very small mass compared to protons.
Electrons have about the same mass as protons.
Electrons are much heavier than protons.
Electrons have about the same mass as neutrons.
(1)
(c)
Which method is used to extract aluminium from aluminium oxide?
Tick ( ) one box.
Method
Tick ( )
Heating aluminium oxide.
Heating aluminium oxide with carbon.
Electrolysis of molten aluminium oxide.
Heating aluminium oxide with copper.
(1)
(Total 4 marks)
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Plantsbrook School
Q5.This question is about lithium and sodium.
(a)
Use the Chemistry Data Sheet to help you to answer this question.
In which group of the periodic table are lithium and sodium?
Group
(1)
(b)
A lithium atom can be represented as
The diagram represents the lithium atom.
(i)
Some particles in the nucleus have a positive charge.
What is the name of these particles?
......................................................................
(1)
(ii)
Some particles in the nucleus have no charge.
What is the name of these particles?
........................................................................
(1)
(iii)
Use the correct answer from the box to complete the sentence.
3
4
7
The mass number of this atom of lithium is
(1)
(c)
Sodium reacts with chlorine to produce sodium chloride.
sodium
+
chlorine
The diagram shows how the reaction happens.
Page 6
sodium chloride
Plantsbrook School
Only the outer electrons are shown.
Draw a ring around the correct answer to complete each sentence.
(i)
gaining
A sodium atom changes into a sodium ion
by
losing
an electron.
sharing
(1)
(ii)
a negative
A sodium ion has
no
charge.
a positive
(1)
(iii)
covalent
The ions in sodium chloride are held together by
strong
electrostatic
magnetic
Page 7
forces.
Plantsbrook School
(1)
(d)
Sodium chloride is an ionic compound.
Tick ( ) two properties of ionic compounds.
Property
Tick ( )
Do not dissolve in water
High melting points
Low boiling points
Strong bonds
(2
(e)
(i)
The formula of sodium chloride is NaCl
Calculate the relative formula mass of sodium chloride.
Relative atomic masses: Na = 23; Cl = 35.5
.................................................................................................................
.................................................................................................................
Relative formula mass = .............................................
(1)
(ii)
Draw a ring around the correct answer to complete each sentence.
ion
The relative formula mass of a substance, in grams, is one
isotop
of the substance.
e
mole
(1)
(f)
Nanoparticles of sodium chloride (salt) are used to flavour crisps.
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Plantsbrook School
What are nanoparticles?
........................................................................................................................
........................................................................................................................
(1)
(Total 12 marks)
Q6.The age of an object can be found using carbon dating.
Carbon dating was used to estimate the age of an Egyptian boat thousands of years old.
By Alex Lbh [CC BY_SA 2.0], via wikimedia commons
Most carbon occurs as the isotope carbon-12 (
Another isotope, carbon-14 (
).
), is used in carbon dating.
What are isotopes?
In your answer you should refer to the numbers of protons, electrons and neutrons in the
isotopes of carbon.
.................................................................................................................................
.................................................................................................................................
.................................................................................................................................
.................................................................................................................................
.................................................................................................................................
.................................................................................................................................
(Total 3 marks)
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Plantsbrook School
Q7.
(a)
Read the article about the use of nanoparticles in sun creams.
Sun creams
Many sun creams use nanoparticles. These sun creams are very good at
absorbing radiation, especially ultraviolet radiation. Owing to the particle size, the
sun creams spread more easily, cover better and save money because you use
less. The new sun creams are also transparent, unlike traditional sun creams
which are white. The use of nanoparticles is so successful that they are now used
in more than 300 sun cream products.
Some sun creams contain nanoparticles of titanium oxide. Normal-sized particles
of titanium oxide are safe to put on the skin.
It is thought that nanoparticles can pass through the skin and travel around the
body more easily than normal-sized particles. It is also thought that nanoparticles
might be toxic to some types of cell, such as skin, bone, brain and liver cells.
(i)
How is the size of nanoparticles different from normal-sized particles of
titanium oxide?
..........................................................................................................................
(1)
(ii)
Suggest how the size of nanoparticles might help them to enter the body more
easily.
..........................................................................................................................
..........................................................................................................................
(1)
(b)
Give two advantages of using nanoparticles in sun creams.
1 .................................................................................................................................
....................................................................................................................................
2 .................................................................................................................................
....................................................................................................................................
(2)
(c)
Why might nanoparticles be dangerous inside the body?
...................................................................................................................................
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Plantsbrook School
...................................................................................................................................
(1)
(Total 5 marks)
Q8.
(a) Copper is a metal.
Explain how it conducts electricity.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
Graphite is a non-metal.
Use the information to explain why graphite conducts electricity.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 5 marks)
Q9.
(a)
helium.
The diagrams represent the atomic structures of two gases, hydrogen and
Page 11
Plantsbrook School
Hydrogen gas is made up of diatomic molecules (molecules with two atoms).
Helium gas exists as single atoms.
(i)
How is a molecule of hydrogen formed from two hydrogen atoms?
(You may use a diagram as part of your answer)
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Why does helium exist only as single atoms?
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b) Hydrogen combines with carbon to form methane.
Each molecule contains four hydrogen atoms strongly bonded to a carbon atom.
Explain why methane has a low boiling point.
.....................................................................................................................................
.....................................................................................................................................
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Plantsbrook School
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 6 marks)
Atoms of calcium, phosphorus and fluorine are represented below, each with its mass
number and proton number.
(a)
Use this information to complete the table.
CALCIUM
Number of protons in the nucleus
20
Number of neutrons in the nucleus
20
PHOSPHOROUS
Number of electrons
FLUORINE
9
16
15
9
(3)
(b)
Calcium and fluorine atoms can combine to form the compound calcium fluoride, CaF2.
The fluoride ion is represented by F–.
(i)
Explain how the fluorine atom forms a fluoride ion.
..........................................................................................................................
..........................................................................................................................
(2)
(ii)
How is the calcium ion represented?
..........................................................................................................................
(2)
(c)
Phosphorus and fluorine form a covalent compound, phosphorus trifluoride.
Complete the sentences below which are about this compound.
Phosphorus trifluoride is made up of phosphorus and fluorine ................................
These are joined together by sharing pairs of ............................................... to form
phosphorus trifluoride ........................................................ .
(3)
(d)
(i)
Sodium chloride, an ionic compound, has a high melting point whereas
paraffin wax, a molecular Page 13compound, melts easily.
Plantsbrook School
Explain why.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(ii)
Molten ionic compounds conduct electricity but molecular compounds are nonconductors, even when liquid.
Explain why.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(Total 14 marks)
Q11.
This question is about oxygen atoms. The periodic table on the Data Sheet may help
you to answer this question.
(a)
(i)
Oxygen atoms have 8 electrons.
Complete the diagram to represent the arrangement of electrons in an oxygen
atom.
Use crosses (×) to represent the electrons.
(1)
(ii)
Name the part of the oxygen atom that is labelled A on the diagram.
...........................................................................................................................
(1)
(b)
Two isotopes of oxygen are oxygen-16 and oxygen-18.
16
18
O
O
8
8
Page 14
Plantsbrook School
oxygen-16
oxygen-18
Explain, in terms of particles, how the nucleus of an oxygen-18 atom is different from the
nucleus of an oxygen-16 atom.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 4 marks)
Q12.
This question is about sodium chloride (common salt) which is an important
chemical.
Sodium chloride can be made by burning sodium in chlorine gas.
(a)
Balance the symbol equation for the reaction of sodium with chlorine.
Na(s)
+
Cl2(g)
→
NaCl(s)
(1)
(b)
(i)
Complete the diagrams below to show the electronic structures of a sodium
and a chlorine atom. (Atomic number of sodium = 11 and chlorine = 17.)
(3)
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Plantsbrook School
(ii)
When sodium reacts with chlorine the sodium atoms are changed into sodium
ions (Na+) and the chlorine atoms are changed into chlorine ions (Cl–).
Explain how:
1.
a sodium atom changes into a sodium ion;
...........................................................................................................................
...........................................................................................................................
(2)
2.
a chlorine atom changes into a chloride ion.
...........................................................................................................................
...........................................................................................................................
(2)
(c) The element potassium is in the same group of the Periodic Table as sodium. Potassium reacts
with chlorine to make potassium chloride which is sometimes used instead of common salt in cooking.
(i)
Predict the formula of potassium chloride.
...........................................................................................................................
(1)
By reference to the electronic structures of potassium and sodium explain:
(ii)
Why the reaction of potassium with chlorine is similar to the reaction of sodium
with chlorine.
...........................................................................................................................
...........................................................................................................................
(1)
(d) The electrolysis of sodium chloride solution is an important industrial process. The diagrams
below show two experiments set up during an investigation of the electrolysis of sodium chloride.
(i)
What would be the reading on the ammeter in experiment 1?
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Plantsbrook School
.................................................... A
(ii)
Explain your answer.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(e)
The equations below show the reactions which take place in experiment 2.
(i)
H2O(1)
→
H+(aq)
2H+(aq)
+
2e–
→
H2(g)
2Cl–(aq)
–
2e–
→
Cl2(g)
+
OH– (aq)
Which substance provides hydrogen ions?
...........................................................................................................................
(1)
(ii)
Name the product formed at:
(A)
the positive electrode;
...........................................................................................................................
(B)
the negative electrode.
...........................................................................................................................
(1)
(Total 15 marks)
Q13.
Electrons, neutrons and protons are sub-atomic particles.
(a)
Complete the six spaces in the following table.
Name of sub-atomic particle
Relative mass
Relative charge
.......................................
1
........................................
.......................................
........................................
0
.......................................
.........................................
(3)
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Plantsbrook School
(b)
An aluminium atom has 13 electrons. How are these arranged in shells around the
nucleus?
....................................................................................................................................
(1)
(c)
Chromium atoms have 24 protons and 28 neutrons.
(i)
How many electrons does each neutral chromium atom have?
...........................................................................................................................
(1)
(ii)
What is the mass number of chromium?
...........................................................................................................................
(1)
(d)
What change occurs to an atom which undergoes the process of reduction in a
chemical reaction?
....................................................................................................................................
....................................................................................................................................
(1)
(e)
The diagram shows part of the ionic lattice of a sodium chloride crystal.
Explain why the ions in this lattice stay in place.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
Page 18
Plantsbrook School
(Total 10 mark)
Q14.
(a)
Atoms are made of sub-atomic particles. Complete the six spaces in the table.
Name of sub-atomic particle
Relative mass
Relative charge
.................................
......................
Neutron
.....................
.......................
.................................
1
.......................
(b)
Complete the spaces in the sentences.
(i)
The atomic number of an atom is the number of ..................................... in its
nucleus and is equal to the number of ..................................................... if the
atom is not charged.
(1)
(ii)
The mass number of an atom is the total number of ................................. and
...................................... in its nucleus.
(1)
(c)
The table gives information about the atoms of three elements.
Number of electrons in:
Name of
element
Chemical
symbol
1st
shell
2nd
shell
3rd
shell
Fluorine
F
2
7
0
Neon
Ne
2
8
0
Sodium
Na
2
8
1
Two of these elements can react together to form a chemical compound.
(i)
What is the name and the formula of this compound?
Page 19
Plantsbrook School
Name ................................................... Formula ..........................................
(2)
(ii)
What type of bonding holds this compound together?
...........................................................................................................................
(1)
(iii)
Explain, in terms of electron transfer, how the bonding occurs in this
compound.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 10 marks
Q15.
(a) The electronic structure of a sodium atom can be written 2,8,1.
Write the electronic structure of a potassium atom in the same way.
.....................................................................................................................................
(1)
(b)
The electronic structure of a sodium atom can also be represented as in the
diagram below.
(i)
Draw a similar diagram for a fluorine atom.
Page 20
Plantsbrook School
(ii)
Draw similar diagrams to show the electronic structure of the particles in
sodium fluoride.
(4)
(Total 5 marks)
Q16.
Brine, a solution containing sodium chloride in water, can be used to manufacture
chlorine, hydrogen and sodium hydroxide. A student sets up a simplified model of the
industrial cell.
(a)
The electron arrangements of some atoms are shown here.
(i)
H
1
O
2.6
Na
2.8.1
C1
2.8.7
Use the relevant electron arrangements to describe the bonding in water.
...........................................................................................................................
Page 21
Plantsbrook School
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Use the relevant electron arrangements to describe the bonding in sodium
chloride.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(b)
Use the atomic structures of
isotopes.
and
to explain the meaning of the term
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 8 marks)
Q17.
Read the article about the use of nanoparticles in sun creams.
Page 22
Plantsbrook School
Sun creams
Many sun creams use nanoparticles. These sun creams are very good at
absorbing radiation, especially ultraviolet radiation. Owing to the particle size, the
sun creams spread more easily, cover better and save money because you use
less. The new sun creams are also transparent, unlike traditional sun creams
which are white. The use of nanoparticles is so successful that they are now used
in more than 300 sun cream products.
Some sun creams contain nanoparticles of titanium oxide. Normal-sized particles
of titanium oxide are safe to put on the skin.
It is thought that nanoparticles can pass through the skin and travel around the
body more easily than normal-sized particles. It is also thought that nanoparticles
might be toxic to some types of cell, such as skin, bone, brain and liver cells.
(a)
Explain why nanoparticles pass through the skin and travel around the body more
easily than normal-sized particles of titanium oxide.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(b)
Explain why sun creams containing nanoparticles should be tested further.
....................................................................................................................................
....................................................................................................................................
(1)
(c)
Suggest why some companies that make sun creams might not want to do more
tests.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(Total 5 marks)
Q18.
The diagrams show three isotopes of potassium.
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Plantsbrook School
(i)
In what way does the atomic structure show you that they are all atoms?
.....................................................................................................................................
.....................................................................................................................................
(1)
(ii)
Explain why these three atoms are called isotopes of potassium.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 4 marks)
Section 2
Q1.
The diagram shows the main parts of an instrumental method called gas chromatography linked to
mass spectroscopy (GC-MS).
Page 24
Plantsbrook School
This method separates a mixture of compounds and then helps to identify each of the compounds
in the mixture.
(a)
In which part of the apparatus:
(i)
is the mixture separated? ...................................................................
(1)
(ii)
is the relative molecular mass of each of the compounds in the mixture measured?
...............................................................................................................
(1)
(b)
(i)
Athletes sometimes take drugs because the drugs improve their performance. One of
these drugs is ephedrine.
Ephedrine has the formula:
C10H15NO
What relative molecular mass (Mr) would be recorded by GC-MS if ephedrine was
present in a blood sample taken from an athlete?
Show clearly how you work out your answer.
Relative atomic masses: H = 1; C = 12; N = 14; O = 16.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
Relative molecular mass = .....................................
(2)
Page 25
Plantsbrook School
(ii)
Another drug is amphetamine which has the formula:
C9H13N
The relative molecular mass (Mr) of amphetamine is 135.
Calculate the percentage by mass of nitrogen in amphetamine.
Relative atomic mass: N = 14
...............................................................................................................
...............................................................................................................
Percentage of nitrogen = ..................................... %
(2)
(c)
Athletes are regularly tested for drugs at international athletics events.
An instrumental method such as GC-MS is better than methods such as titration.
Suggest two reasons why.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(d)
When a blood sample is taken from an athlete the sample is often split into two portions.
Each portion is tested at a different laboratory.
Suggest why.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 10 marks)
Q2.
An electric current was passed through dilute sulphuric acid. The apparatus used is shown.
Oxygen was formed at the anode.
Page 26
Plantsbrook School
(a)
What name is given to solutions which decompose when electricity is passed through them?
.....................................................................................................................................
(1)
(b)
The ionic equation for the reaction at the anode is:
4OH– → 2H2O + O2 + 4e–
Explain this type of reaction.
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
Write a balanced ionic equation for the reaction at the cathode.
.....................................................................................................................................
(2)
(d)
What happens to the concentration of the sulphuric acid as the electricity is passed through
it? Explain your answer.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 8 marks)
Page 27
Plantsbrook School
Q3.
(a)
Citric acid produces hydrogen ions in aqueous solution.
These ions can be represented as H+(aq).
Complete this sentence.
The (aq) means that the acid has been dissolved in .................................................. .
(1)
(b)
The diagram represents a hydrogen atom, H.
Use the diagram to explain why a hydrogen ion, H+, is a proton.
.....................................................................................................................................
.....................................................................................................................................
(1)
(c)
Citric acid is a weak acid.
Draw a ring around the correct answer to complete the sentence.
has a low boiling point.
The word weak means that the acid
is dilute.
is partially ionised in water.
(1)
(d)
A student measured the pH of four acids, A, B, C and D.
The acids were the same
Page 28concentration. The same quantity of
Plantsbrook School
magnesium ribbon was added to each of the acids. The volume of gas produced after 5
minutes was recorded.
The results are shown in the table.
Acid
pH
Volume of gas in cm3
A
2
18
B
5
6
C
1
24
D
4
12
(i)
State one way in which the student made sure that the experiment was fair.
...........................................................................................................................
(1)
(ii)
Use the results to arrange the acids, A, B, C and D in order of decreasing acid
strength.
Most acidic ........................................................................................ Least acidic.
(1)
(e)
When acids react with alkalis, the hydrogen ions from the acid react with the hydroxide ions
from the alkali.
(i)
Which one of the following represents the formula of a hydroxide ion?
Draw a ring around your answer.
H–
O–
OH–
(1)
(ii)
Draw a ring around the correct answer to complete the sentence.
acidic.
A solution with more hydrogen ions than hydroxide ions is
alkaline.
neutral.
(1)
(Total 7 marks)
Page 29
Plantsbrook School
Q4.
The salt sodium hydrogen phosphate (Na2HPO4) is used as a softening agent in
processed cheese.
It can be made by reacting phosphoric acid (H3PO4) with an alkali.
(a)
Complete the name of an alkali that could react with phosphoric acid to make sodium
hydrogen phosphate.
....................................... hydroxide
(1)
(b)
What is the name given to a reaction in which an acid reacts with an alkali to make a salt?
.....................................................................................................................................
(1)
(c)
How would the pH change when alkali is added to the phosphoric acid solution?
.....................................................................................................................................
.....................................................................................................................................
(1)
(d)
What ions are present when any acid is dissolved in water?
.....................................................................................................................................
(1)
(e)
What ions are present when any alkali is dissolved in water?
.....................................................................................................................................
(1)
Page 30
Plantsbrook School
(f)
Write a chemical equation for the reaction which takes place between the ions you have
named in (e) and (f).
.....................................................................................................................................
(1)
(Total 6 marks)
Q5.
The diagrams show what happens when an acid is added to an alkali.
(a)
What is present in the flask at stage 2, besides universal indicator and water?
.....................................................................................................................................
(1)
(b)
Write an ionic equation to show how water is formed in this reaction and state the sources of
the ions.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 4 marks)
Page 31
Plantsbrook School
Q6.Rhubarb powder was used as a drug in the 1880s.
A bottle labelled ‘Rhubarb Powder’ was found in a museum. Scientists were asked to make sure
that the substance in the bottle was rhubarb powder.
The scientists used an instrumental method called GC-MS. This identified compounds in the
rhubarb powder.
(a)
Draw a ring around the correct answer in the box to complete the sentence.
gas
In this instrumental method the initials GC represent
general
chromatography.
glass
(1)
(b)
Scientists often use instrumental methods instead of chemical tests to analyse substances.
Choose the two reasons why.
Tick (
) two boxes.
Instrumental methods . . .
Tick (
)
allow colour changes to be seen.
are faster.
are more accurate.
use more of the substance.
(2)
Page 32
Plantsbrook School
(c)
Rhubarb contains oxalic acid.
The formula of oxalic acid is H2C2O4
Relative atomic masses (Ar ): H=1, C=12, O=16
Draw a ring around the correct answer in each box to complete the question.
29
(i)
The relative formula mass (Mr ) of oxalic acid is
90
192
(1)
ion.
(ii)
The relative formula mass of oxalic acid in grams is called one
mole.
particle.
(1)
(Total 5 marks)
Q7.
(i)
Which acid from the list should the student add to sodium hydroxide solution to make
sodium sulphate?
ethanoic acid
hydrochloric acid
nitric acid
sulphuric acid
.....................................................................................................................................
(1)
(ii)
When the acid was added to the alkali the beaker became warm.
Name the type of reaction that releases heat.
.....................................................................................................................................
(1)
(iii)
Use the Data Sheet to help you to write the formula of sodium sulphate.
Formula: .....................................................................................................................
(1)
(Total 3 marks)
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Plantsbrook School
Q8.A swimming pool was closed after two chemicals leaked into the pool.
Fire-fighters were asked to investigate the leak. They had to wear special suits.
By fairfaxcounty [CC BY-ND 2.0], via Flickr
The two chemicals that leaked were sodium hypochlorite and sulfuric acid.
The chemicals reacted together to make chlorine gas.
(a)
(i)
Which ion makes sulfuric acid acidic?
Draw a ring around the correct answer.
hydrogen ion (H+)
hydroxide ion (OH–)
sulfate ion (SO42–)
(1)
(ii)
Draw a ring around the correct answer in the box to complete the sentence.
A solution of sodium hypochlorite is alkaline.
4
The pH of sodium hypochlorite solution is
7
11
(1)
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Plantsbrook School
(iii)
Draw a ring around the correct answer in the box to complete the sentence.
combustion.
The reaction between an acid and an alkali is called
decomposition.
neutralisation.
(1)
(b)
The fire-fighters wore special suits.
Suggest why.
........................................................................................................................
........................................................................................................................
(1)
(c)
Sodium chloride solution can be electrolysed.
Sodium hypochlorite can be made using two products of the electrolysis.
Tick (
) two correct products of the electrolysis of sodium chloride solution.
Product
Tick (
)
Chlorine
Sodium
Sodium sulfate
Sodium hydroxide
(2)
(Total 6 marks)
Q9.
Bordeaux Mixture controls some fungal infections on plants.
A student wanted to make some Bordeaux Mixture.
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Plantsbrook School
(a)
The student knew that calcium oxide could be made by heating limestone. Limestone
contains calcium carbonate, CaCO3.
(i)
Write the word equation for this reaction.
...........................................................................................................................
(1)
(ii)
What type of reaction is this?
...........................................................................................................................
(1)
(b)
The student knew that copper sulphate, CuSO4, could be made by the following general
reaction.
acid + base → salt + water
(i)
What type of reaction is this?
...........................................................................................................................
(1)
(ii)
The base used is copper oxide. Name and give the chemical formula of the acid used.
Name ................................................................................................................
Chemical formula .............................................................................................
(2)
(c)
The student wrote about how the
Page 36copper sulphate was made.
Plantsbrook School
“Some of the acid was warmed. Copper oxide was added. The mixture was stirred. More
copper oxide was added until no more would react. The mixture was then filtered.”
(i)
Why was the acid warmed?
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Copper oxide was added until no more would react. Explain why.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
The filtration apparatus is shown.
Describe and explain what happens as the mixture is filtered.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 10 marks)
Q10.
Ammonia has the formula NH3. It is made from nitrogen and hydrogen.
Ammonia dissolves in water to form a solution with a pH of 10.
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Plantsbrook School
(a)
What does this pH value tell you about ammonia solution?
........................................................................................................................
........................................................................................................................
(1)
(b)
In industry a large amount of ammonia is neutralised by an acid to make ammonium nitrate.
(i)
What type of substance is ammonium nitrate?
...............................................................................................................
(1)
(ii)
Which acid is added to ammonia to make ammonium nitrate?
...............................................................................................................
(1)
(iii)
Draw a ring around the main use of ammonium nitrate.
fertiliser
lubricating oil
medicine
plastic
(1)
(c)
Instant cold packs are used to treat sports injuries.
One type of cold pack has a plastic bag containing water. Inside the bag is a smaller bag
containing ammonium nitrate.
The outer bag is squeezed so that the inner bag bursts. The ammonium nitrate dissolves in
the water. This process is endothermic.
Explain why the bag becomes cold.
........................................................................................................................
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Plantsbrook School
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 6 marks)
Q11.The electrolysis of sodium chloride solution is an industrial process.
The diagram shows the apparatus used in a school experiment.
(a)
One of the products of the electrolysis of sodium chloride solution is hydrogen.
(i)
Why do hydrogen ions move to the negative electrode?
...............................................................................................................
...............................................................................................................
(1)
(ii)
How does a hydrogen ion change into a hydrogen atom?
...............................................................................................................
...............................................................................................................
(1)
(b)
Hydrogen is used to make ammonia (NH3).
Complete the diagram to show the bonding in ammonia.
Use dots (●) and crosses (x) to show electrons.
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Plantsbrook School
Show only outer shell electrons.
(2)
(c)
The table shows the ions in sodium chloride solution.
Positive ions
Negative ions
hydrogen
chloride
sodium
hydroxide
In industry, some of the waste from the electrolysis of sodium chloride solution is alkaline
and has to be neutralised.
(i)
Which ion makes the waste alkaline?
...............................................................................................................
(1)
(ii)
This waste must be neutralised.
Write the ionic equation for the neutralisation reaction.
...............................................................................................................
(1)
(d)
In this question you will be assessed on using good English, organising information clearly
and using specialist terms where appropriate.
The electrolysis of sodium chloride solution also produces chlorine and sodium hydroxide.
In industry, the electrolysis of sodium chloride solution can be done in several types of
electrolysis cell.
Some information about two different types of electrolysis cell is given below.
Mercury cell
Cost of construction
Expensive
Page 40
Membrane cell
Relatively cheap
Plantsbrook School
Additional substances used
Mercury, which is recycled.
Mercury is toxic so any traces
of mercury must be removed
from the waste
Membrane, which is made
of a polymer. The
membrane must be
replaced every 3 years.
Amount of electricity used for
each tonne of chlorine
3400
produced in kWh
2950
Quality of chlorine produced
Pure
Needs to be liquefied and
distilled to make it pure.
Quality of sodium hydroxide
solution produced
50% concentration. Steam is
used to concentrate the
sodium hydroxide solution
produced.
30% concentration. Steam
is used to concentrate the
sodium hydroxide solution
produced.
Use the information and your knowledge and understanding to compare the environmental
and economic advantages and disadvantages of these two types of electrolysis cell.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(6)
(Total 12 marks)
Q12.A company making sweets uses different colour additives in different countries. In some countries
the company uses Allura Red to colour sweets red.
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Plantsbrook School
Some European countries recommend children do not eat Allura Red. In Europe the company
uses Cochineal instead of Allura Red to colour sweets red.
A different red food colouring, B, was compared with Cochineal and Allura Red using paper
chromatography.
The diagram shows the results.
(a)
(i)
How can you tell from the diagram that the three food colourings are not the same?
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(ii)
The red food colouring, B, is not suitable for use in sweets sold in European countries.
Suggest one reason why.
...............................................................................................................
...............................................................................................................
(1)
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Plantsbrook School
(b)
Give two reasons why food scientists use instrumental methods instead of paper
chromatography to analyse food colourings.
1 .....................................................................................................................
........................................................................................................................
2 .....................................................................................................................
........................................................................................................................
(2)
(Total 5 marks)
Q13.Electroplating is used to coat a cheap metal with a thin layer of an expensive metal.
In the diagram a teaspoon made of nickel is being coated with silver.
Silver nitrate (AgNO3) contains silver ions (Ag+) and nitrate ions (NO3−).
(a)
Solid silver nitrate, AgNO3(s), does not conduct electricity.
Choose the correct answer in the box to complete the sentence.
are too big
cannot move
are too small
Solid silver nitrate does not conduct electricity because the ions ................
........................................................................................................................
(1)
(b)
Draw a ring around the correct answer to complete each sentence.
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Plantsbrook School
no charge.
(i)
Silver ions move to the negative electrode because they have
a negative charge.
a positive charge.
(1)
atoms.
(ii)
When silver ions reach the negative electrode they turn into silver
compounds.
molecules.
(1)
(Total 3 marks)
Q14.Rhubarb powder was used as a drug in the 1880s.
A bottle labelled ‘Rhubarb Powder’ was found in a museum.
Scientists were asked to make sure the substance was rhubarb powder.
The scientists used an instrumental method known as GC–MS to identify compounds in the
rhubarb powder.
(a)
Give two reasons why scientists use instrumental methods and not chemical tests to analyse
substances.
1 .....................................................................................................................
........................................................................................................................
2 .....................................................................................................................
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Plantsbrook School
........................................................................................................................
(2)
(b)
Rhubarb contains oxalic acid and malic acid.
Gas chromatography can be used to separate these acids.
Explain why.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(Total 4 marks)
Section 3
Q1.
Calculate the percentage of iron in iron sulphate (FeSO 4).
(Relative atomic masses: Fe = 56, O = 16, S = 32)
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
Percentage of iron in iron sulphate = ..........................%
(Total 3 marks)
Q2.A cricketer uses zinc oxide sunblock on his face.
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Plantsbrook School
By TonyPatterson [CC BY-2.0], via Flickr
(a)
The formula of zinc oxide is ZnO.
The relative formula mass (Mr ) of zinc oxide is 81
Relative atomic masses (Ar ): O = 16, Zn = 65
Calculate the percentage of zinc in zinc oxide.
Use the equation to help you answer this.
×
100
percentage (%) of element =
Show clearly how you work out your answer.
........................................................................................................................
........................................................................................................................
........................................................................................................................
Percentage of zinc = ..................................................%
(2)
(b)
Modern sun creams contain nanoparticles.
(i)
How are nanoparticles different in size from normal sized particles?
...............................................................................................................
...............................................................................................................
(1)
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Plantsbrook School
(ii)
A nanoparticle has a high surface area to volume ratio.
Suggest why nanoparticles are useful in sun creams.
...............................................................................................................
...............................................................................................................
(1)
(Total 4 marks)
Q3.
(a)
A chemist was asked to identify a nitrogen compound. The chemist carried out an
experiment to find the relative formula mass (Mr) of the compound.
The Mr of the compound was 44.
Relative atomic masses: N = 14, O = 16
Draw a ring around the formula of the compound.
NO
NO2
N2O4
N2O
(1)
(b)
Potassium nitrate is another nitrogen compound. It is used in fertilisers. It has the formula
KNO3.
The Mr of potassium nitrate is 101.
Calculate the percentage of nitrogen by mass in potassium nitrate.
Relative atomic mass: N = 14.
.....................................................................................................................................
.....................................................................................................................................
Percentage of nitrogen = .............................. %
(2)
(Total 3 marks)
Q4.
Toothpastes often contain fluoride ions to help protect teeth from attack by bacteria.
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Plantsbrook School
Some toothpastes contain tin(II) fluoride.
This compound has the formula SnF2 .
(a)
Calculate the relative formula mass (Mr) of SnF2.
Relative atomic masses: F = 19; Sn = 119
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
Relative formula mass (Mr) = ..........................................
(2)
(b)
Calculate the percentage by mass of fluorine in SnF 2.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
Percentage by mass of fluorine = .......................................... %
(2)
(c)
A tube of toothpaste contains 1.2 g of SnF2.
Calculate the mass of fluorine in this tube of toothpaste.
....................................................................................................................................
....................................................................................................................................
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Plantsbrook School
....................................................................................................................................
....................................................................................................................................
Mass of fluorine = .......................................... g
(1)
(d)
The diagram represents the electron arrangement of a fluorine atom.
Explain how a fluorine atom can change into a fluoride ion, F –.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(2)
(Total 7 marks)
Q5.
The information on the Data Sheet will be helpful in answering this question.
(a)
Calculate the formula mass (Mr) of the compound iron (III) oxide, Fe2O3.
(Show your working.)
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(b)
Calculate the mass of iron produced when 32g of iron (III) oxide is completely reduced by
aluminium.
The reaction is shown in the
symbol equation:
Page 49
Plantsbrook School
Fe2O3
+
2Al
→
2Fe
+
Al2O3
(Show your working.)
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Answer = ..................................... grams
(3)
(Total 6 marks)
Q6.A cricketer uses zinc oxide sunblock on his face.
By TonyPatterson [CC BY-2.0], via Flickr
(a)
Zinc oxide can be made by reacting zinc with oxygen.
The balanced symbol equation for the reaction is:
2Zn
(i)
+
O2
→
2ZnO
A tube of sunblock contained 40.5 g of zinc oxide.
Calculate the mass of zinc that would be needed to make 40.5 g of zinc oxide.
Relative atomic masses (Ar ): O=16, Zn=65
...............................................................................................................
...............................................................................................................
Page 50
Plantsbrook School
...............................................................................................................
...............................................................................................................
...............................................................................................................
Mass of zinc = ............................................. g
(3)
(ii)
If the mass of zinc you calculated in part (a)(i) is used, the mass of zinc oxide obtained
may be less than 40.5 g.
Suggest one reason why.
...............................................................................................................
...............................................................................................................
(1)
(b)
(i)
Many sun creams contain nanoparticles of zinc oxide.
What are nanoparticles?
...............................................................................................................
(1)
(ii)
Nanoparticles are more useful than normal sized particles in sun creams.
Explain why.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(Total 7 marks)
Q7.
(a)
The formula for ammonia is NH3. What does the formula tell you about each molecule
of ammonia?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
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Plantsbrook School
.....................................................................................................................................
(3)
(b)
Ammonia is used to make nitric acid (HNO3). Calculate the formula mass (Mr) for nitric acid.
(Show your working).
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 6 marks)
Q8.
Iron ore contains iron oxide.
(i)
Calculate the relative formula mass of iron oxide, Fe2O3.
Relative atomic masses: O = 16; Fe = 56.
.....................................................................................................................................
.....................................................................................................................................
Answer = ................................................
(2)
(ii)
Calculate the percentage by mass of iron in iron oxide.
.....................................................................................................................................
Percentage of iron = .......................................... %
(2)
(iii)
Calculate the mass of iron that could be extracted from 1000 kg of iron oxide.
Use your answer to part (c) (ii) to help you with this calculation.
.....................................................................................................................................
Mass of iron = ................................................... kg
(1)
(Total 5 marks)
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Plantsbrook School
Q9.
Ammonium nitrate is an important fertiliser. It is made by reacting nitric acid with the alkali
ammonia.
(i)
State the type of reaction taking place.
...........................................................................................................................
(1)
(ii)
The equation for this reaction is:
NH3 + HNO3
→
NH4NO3
Calculate the number of tonnes of ammonium nitrate that can be made from
68 tonnes of ammonia.
(Relative atomic masses: H = 1, N = 14, O = 16)
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(Total 4 marks)
Q10.
Calcium oxide (quicklime) is made by heating calcium carbonate (limestone).
calcium carbonate → calcium oxide + carbon dioxide
100 g
?
44 g
(a)
44 grams of carbon dioxide is produced when 100 grams of calcium carbonate is heated.
Calculate the mass of calcium oxide produced when 100 grams of calcium carbonate
is heated.
....................................................................................................................................
mass ......................... g
(1)Page
53
Plantsbrook School
(b)
What mass of carbon dioxide could be made from 100 tonnes of calcium carbonate?
mass ....................... tonnes
(1)
(Total 2 marks)
Q11.
Petrol is a mixture of hydrocarbons such as octane, C8H18
When petrol is burned in a car engine, a large amount of carbon dioxide is produced.
This car uses 114 g of petrol to travel one mile.
Calculate the mass of carbon dioxide produced when this car travels one mile.
Assume that petrol is octane and that combustion is complete.
(Relative atomic masses: H = 1; C = 12; O = 16)
The combustion of octane can be represented by this equation.
C8H18 + 12
O2 → 8CO2 + 9H2O
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
Mass of carbon dioxide = ........................ g
(Total 3 marks)
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Plantsbrook School
Q12.
Calcium carbonate tablets are used to treat people with calcium deficiency.
(a)
Calculate the relative formula mass (Mr) of calcium carbonate.
Relative atomic masses: C = 12; O = 16; Ca = 40.
.....................................................................................................................................
.....................................................................................................................................
Relative formula mass = ..............................
(2)
(b)
Calculate the percentage of calcium in calcium carbonate, CaCO3.
.....................................................................................................................................
.....................................................................................................................................
Percentage of calcium = .......................... %
(2)
(c)
Calculate the mass of calcium in each tablet.
.....................................................................................................................................
.....................................................................................................................................
Mass of calcium = .................................... g
(2)
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Plantsbrook School
(d)
An unwanted side effect of this medicine is that it can cause the patient to have ‘wind’ (too
much gas in the intestine).
The equation below represents the reaction between calcium carbonate and hydrochloric
acid (the acid present in the stomach).
CaCO3 (s) + 2HCl (aq) →CaCl2 (aq) + H2O (l) + CO2 (g)
Suggest why the patient may suffer from ‘wind’.
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 7 marks)
Q13.
Aspirin tablets have important medical uses.
(a)
Aspirin is made when salicylic acid reacts with ethanoic anhydride.
The equation for this reaction is:
C7H6O3
+
salicylic acid
C4H6O3
→
C9H8O4
aspirin
+
CH3COOH
Calculate the maximum mass of aspirin that could be made from 100 g of salicylic acid.
Show clearly how you work out your answer.
The relative formula mass (Mr) of salicylic acid (C7H6O3) is 138.
The relative formula mass (Mr) of aspirin (C9H8O4) is 180.
........................................................................................................................
........................................................................................................................
Page 56
Plantsbrook School
........................................................................................................................
........................................................................................................................
Maximum mass of aspirin = .................................... g
(2)
(b)
(i)
In an experiment a chemist calculated that the maximum yield of aspirin is 400 g.
The chemist did the experiment but only made 250 g of aspirin.
Calculate the percentage yield of aspirin for this experiment.
Show clearly how you work out your answer.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
Percentage yield of aspirin = ........................... %
(2)
(ii)
Suggest one possible reason why the chemist did not have a percentage
yield of 100%.
...............................................................................................................
...............................................................................................................
(1)
(c)
The use of a catalyst might reduce costs in the industrial production of aspirin.
Suggest how.
........................................................................................................................
........................................................................................................................
(1)
(Total 6 marks)
Q14.
Aspirin tablets have important medical uses.
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Plantsbrook School
A student carried out an experiment to make aspirin. The method is given below.
1.
2.
3.
4.
5.
6.
7.
8.
Weigh 2.00 g of salicylic acid.
Add 4 cm3 of ethanoic anhydride (an excess).
Add 5 drops of concentrated sulfuric acid.
Warm the mixture for 15 minutes.
Add ice cold water to remove the excess ethanoic anhydride.
Cool the mixture until a precipitate of aspirin is formed.
Collect the precipitate and wash it with cold water.
The precipitate of aspirin is dried and weighed.
(a)
The equation for this reaction is shown below.
C7H6O3
+
salicylic acid
C4H6O3
→
C9H8O4 +
aspirin
CH3COOH
Calculate the maximum mass of aspirin that could be made from 2.00 g of salicylic acid.
The relative formula mass (Mr) of salicylic acid, C7H6O3, is 138
The relative formula mass (Mr) of aspirin, C9H8O4, is 180
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Maximum mass of aspirin = .............................. g
(2)
(b)
The student made 1.10 g of aspirin from 2.00 g of salicylic acid.
Calculate the percentage yield of aspirin for this experiment.
(If you did not answer part (a), assume that the maximum mass of aspirin that can be made
from 2.00 g of salicylic acid is 2.50 g. This is not the correct answer to part (a).)
Page 58
Plantsbrook School
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Percentage yield of aspirin = .............................. %
(2)
(c)
Suggest one possible reason why this method does not give the maximum amount of
aspirin.
.....................................................................................................................................
.....................................................................................................................................
(1)
(d)
Concentrated sulfuric acid is a catalyst in this reaction.
Suggest how the use of a catalyst might reduce costs in the industrial production of aspirin.
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 6 marks)
Q15.
Liquefied petroleum gases such as propane and butane are used as heating fuels for
caravans, boats and barbecues.
(a)
Propane and butane have no smell, so for safety reasons a very small amount of thioethanol
– the smelliest substance known – is added, even though it is toxic in large concentrations.
Suggest one safety reason why
thioethanol is added to propane and butane.
Page 59
Plantsbrook School
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
Suggest how mass spectrometry could be used to distinguish between propane (C 3H8) and
butane (C4H10).
.....................................................................................................................................
.....................................................................................................................................
(1)
(c)
When 0.4 g of a hydrocarbon gas was completely burned in oxygen, 1.1 g of carbon dioxide
and 0.9 g of water were the only products.
Relative formula masses: CO2 = 44; H2O = 18.
Use this information to calculate the number of moles of carbon dioxide and of water produced in
this reaction. Use your answers to calculate the empirical formula of this hydrocarbon.
You must show all your working to gain full marks.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
Empirical formula is ..............................
(4)
(Total 6 marks)
Q16.
Limestone (CaCO3) is a raw material. On strong heating it is converted to calcium oxide which
is a very useful substance.
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Plantsbrook School
(a)
Calculate the formula mass (Mr) of calcium carbonate.
.....................................................................................................................................
Mr of calcium carbonate = ...............................................
(2)
(b)
About 60 million tonnes of calcium oxide is made in Britain each year.
Calculate the mass of calcium carbonate needed to make this amount of calcium oxide.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
Mass of calcium carbonate needed = .............................. million tonnes
(4)
(c)
Water is added to some of the calcium oxide produced in a process known as ‘slaking’. The
product of this reaction is used to make plaster.
CaO(s) + H2O(1)→ Ca(OH)2(s)
(i)
Give the chemical name of Ca(OH)2.
..........................................................................................................................
(1)
(ii)
What is the physical state of the Ca(OH)2 formed in the reaction?
..........................................................................................................................
(1)
(Total 8 marks)
Page 61
Plantsbrook School
Q17.
The following passage was taken from a chemistry textbook.
Germanium is a white, shiny, brittle element. It is used in the electronics industry because it is able
to conduct a small amount of electricity.
It is made from germanium oxide obtained from flue dusts of zinc and lead smelters.
The impure germanium oxide from the flue dusts is changed into germanium by the process
outlined below.
STEP 1
The germanium oxide is reacted with hydrochloric acid to make germanium
tetrachloride. This is a volatile liquid in which the germanium and chlorine
atoms are joined by covalent bonds.
STEP 2
The germanium tetrachloride is distilled off from the mixture.
STEP 3
The germanium tetrachloride is added to an excess of water to produce
germanium oxide and hydrochloric acid.
STEPS 1 to 3
are repeated several times.
STEP 4
The pure germanium oxide is reduced by hydrogen to form germanium.
(a)
Balance the equation below which represents the reaction in step 1.
GeO2
+
............ HCl
→
GeCl4
+
............ H2O
(1)
(b)
Write a word equation for the reaction in step 3.
.....................................................................................................................................
(1)
(c)
Suggest why steps 1 to 3 are repeated several times.
.....................................................................................................................................
.....................................................................................................................................
(1)
(d)
The equation which represents the reaction in step 4 is shown below.
GeO2
(i)
+
2H2
→
Ge
+
2H2O
Explain what is meant by the term ‘reduced’.
...........................................................................................................................
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Plantsbrook School
...........................................................................................................................
(1)
(ii)
Calculate the mass of germanium which could be made from 525 g of germanium
oxide. (Relative atomic masses: Ge = 73; O = 16).
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
Mass ......................................... g
(3)
(e)
Germanium is difficult to classify as either a metal or a non-metal.
(i)
Give as much evidence as you can from the information in this question to support the
view that germanium is a metal. Explain your answer as fully as you can.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(ii)
Give as much evidence as you can from the information in this question to support the
view that germanium is a non-metal. Explain your answer as fully as you can.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(Total 13 marks)
Q18.
Perfumes contain a mixture of chemicals.
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The main ingredients of perfumes are a solvent and a mixture of fragrances.
(a)
A sample of the solvent used in one perfume contained 0.60 g of carbon, 0.15 g of hydrogen
and 0.40 g of oxygen.
Relative atomic masses: H = l; C = 12; O = 16.
Calculate the empirical (simplest) formula of the solvent.
You must show all of your working to gain full marks for this question.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(b)
Solvent molecules evaporate easily.
Explain why substances made of simple molecules evaporate easily.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
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Plantsbrook School
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
Most companies claim that their perfumes have been tested on skin. A study was made of
the tests they used. The study found that each company used different tests.
The perfumes were tested in the companies’ own laboratories and not by independent
scientists.
Some companies did not give any information about the tests that they had used.
(i)
Suggest why companies test their perfumes on skin.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Did the study show that the tests made by the different companies were valid and
reliable?
Explain your answer.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 9 marks)
Section 4
Q1.
A student heated some hydrated copper sulfate crystals.
The equation for this reaction is shown below.
CuSO4.5H2O(s)
hydrated copper sulfate crystals
CuSO4(s)
+
anhydrous copper sulfate
The diagram shows the apparatus used.
Page 65
5H2O(1)
water
Plantsbrook School
(a)
Name liquid A ......................................................................
(1)
(b)
What helped the vapour to condense into liquid A?
.....................................................................................................................................
.....................................................................................................................................
(1)
(c)
Put a tick ( ) next to the correct meaning of the symbol
Meaning
( )
equal amounts of reactants and products
exothermic reaction
reversible reaction
(1)
(d)
The student weighed the copper sulfate before and after it was heated.
The experiment was repeated and the two sets of results are shown in the table.
Mass of copper sulfate before Mass of copper sulfate after
heating in grams
heating in grams
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Mass lost in grams
Plantsbrook School
2.50
1.65
0.85
2.50
1.61
0.89
(i)
Draw a ring around the average mass lost for these two sets of results.
0.85 g
0.87 g
0.89 g
(1)
(ii)
The student used the same mass of copper sulfate each time but the mass lost was
different.
Put a tick ( ) next to the two reasons which could explain why the mass lost is
different.
Reason
( )
The student used different test tubes for the two experiments.
The student made errors in weighing during the experiments.
The student used more ice in one of the experiments.
The student did not heat the copper sulfate for long enough in one of the
experiments.
(2)
(e)
Anhydrous copper sulfate is used to test for water.
Use words from the box to complete the sentence.
blue
green
red
white
Water changes the colour of anhydrous copper sulfate from ............................................
to ............................................. .
(2)
(Total 8 marks)
Q2.
Read the information in the box.
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Plantsbrook School
Flash powder is used to produce special effects at pop concerts.
Flash powder contains aluminium. The powder burns with a bright white flame
and gives out lots of heat and light. It also produces white smoke.
The flash powder is placed on stage in a special container. At the bottom of
the container there is a thin piece of wire. When the flash is needed, electricity
is passed through the wire. The wire gets hot and starts the aluminium
burning.
By russelljsmith [CC BY 2.0], via Flickr
(a)
When aluminium burns the reaction is exothermic.
What is the meaning of exothermic?
........................................................................................................................
........................................................................................................................
(1)
(b)
The hot wire provides energy to start the aluminium burning.
What is the name given to the heat energy needed to start a chemical reaction?
............................................................ energy
(1)
(c)
The white smoke produced is aluminium oxide.
Aluminium oxide contains aluminium ions (Al3+) and oxide ions (O2–).
(i)
Complete the diagram to show the electronic structure of an oxide ion.
The atomic number of oxygen = 8
Use crosses (x) to represent the electrons.
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Plantsbrook School
(1)
(ii)
The bonding in aluminium oxide is ionic.
What causes the aluminium ions and oxide ions to be held together strongly?
...............................................................................................................
...............................................................................................................
(1)
(Total 4 marks)
Q3.
Read the article and then answer the questions that follow.
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Plantsbrook School
Hydrogen fuel for cars?
Hydrogen is an excellent fuel. It can be made by the electrolysis of potassium hydroxide
solution.
Hydrogen gas can be stored under pressure in a cylinder but a leak of the gas could
cause an explosion.
It has been found that lithium nitride can absorb and then release large volumes of
hydrogen. A chemical reaction takes place between the hydrogen and the lithium nitride.
The hydrogen is held in the resulting compounds by chemical bonds.
The problem is that the rate at which hydrogen is absorbed and then released from
normal sized particles of lithium nitride is slow.
Recently scientists have made ‘nanosized’ particles of lithium nitride. These particles
absorb hydrogen in the same way as normal sized lithium nitride particles. The
‘nanosized’ particles have the advantage that they absorb and release the hydrogen
much faster when needed in the fuel cell.
It is hoped that ‘nanosized’ particles of lithium nitride may provide a safe method of
storing hydrogen in the future.
(a)
Hydrogen is produced at the negative electrode during the electrolysis of potassium
hydroxide solution.
(i)
Why are hydrogen ions attracted to the negative electrode?
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Potassium ions are also attracted to the negative electrode.
Explain why hydrogen gas is formed but not potassium.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(1)
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Plantsbrook School
(b)
Lithium nitride is made by reacting lithium with nitrogen.
Balance the equation for this reaction.
.......... Li + N2 → .......... Li3N
(1)
(c)
(i)
The equation for the reaction of lithium nitride with hydrogen is:
Li3N + 2H2
LiNH2 + 2LiH
What feature of this reaction allows the hydrogen to be released?
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
Hydrogen stored in a fuel tank filled with lithium nitride would be safer in an accident
than a cylinder full of hydrogen.
Suggest and explain why.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(d)
Lithium nitride is an ionic compound which contains lithium ions (Li+) and nitride ions (N3–).
(i)
The formation of a lithium ion from a lithium atom is an oxidation reaction.
Explain why.
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
The diagram shows the electronic structure of a nitrogen atom.
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Plantsbrook School
Complete the diagram below to show the electronic structure of a nitride ion (N 3–).
(1)
(Total 8 marks)
Q4.This question is about compounds of copper.
(a)
A student made some copper(II) sulfate crystals.
The flow diagram shows the stages of the preparation of copper(II) sulfate crystals.
Stage 1
(i)
Stage 2
Stage 3
The reaction mixture is heated in Stage 1.
Suggest why.
...............................................................................................................
...............................................................................................................
(1)
(ii)
Complete the equation for this reaction.
CuO + ................................. → CuSO4 + .................................
(2)
(iii)
How would the student remove the unreacted copper(II) oxide in Stage 2?
...............................................................................................................
...............................................................................................................
(1)
(iv)
How would the student
obtain copper(II) sulfate crystals from the
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Plantsbrook School
copper(II) sulfate solution in Stage 3?
...............................................................................................................
(1)
(v)
The mass of crystals obtained was less than the student had calculated.
Suggest one reason why.
...............................................................................................................
...............................................................................................................
(1)
(b)
The student heated the blue copper(II) sulfate crystals.
The word equation for the reaction is shown below.
(i)
hydrated copper(II) sulfate
anhydrous copper(II) sulfate
blue
white
What does the symbol
+ water
mean ?
...............................................................................................................
(1)
(ii)
300 J of energy are taken in when some blue copper(II) sulfate crystals are heated.
What is the energy change when an excess of water is added to the anhydrous
copper(II) sulfate produced?
...............................................................................................................
...............................................................................................................
(2)
(c)
A sample of copper nitride contains 3.81 g of copper and 0.28 g of nitrogen.
Calculate the empirical formula.
You must show all your working to get full marks.
Relative atomic masses (Ar): N = 14; Cu = 63.5.
........................................................................................................................
........................................................................................................................
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Plantsbrook School
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
Empirical formula = ..................................................
(4)
(Total 13 marks)
Q5.
The diagram shows some magnesium ribbon burning.
(a)
Choose words from the list to complete the sentences below.
electrical
an endothermic
heat
light
an exothermic
a neutralisation
kinetic
a reduction
When magnesium burns, it transfers .........................................................................
and ............................................................................ energy to the surroundings.
We say that it is .................................................................................. reaction.
(3)
(b)
Complete the word equation for the reaction.
magnesium +
__________________________
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Plantsbrook School
magnesium oxide
(1)
(Total 4 marks)
Q6.
Instant cold packs are used to treat sports injuries.
One type of cold pack has a plastic bag containing water. Inside this bag is a smaller bag
containing ammonium nitrate.
The outer bag is squeezed so that the inner bag bursts. The pack is shaken and quickly gets very
cold as the ammonium nitrate dissolves in the water.
(a)
One of the statements in the table is correct.
Put a tick ( ) next to the correct statement.
Statement
( )
The bag gets cold because heat energy is given out to the surroundings.
The bag gets cold because heat energy is taken in from the surroundings.
The bag gets cold because plastic is a good insulator.
(1)
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Plantsbrook School
(b)
Draw a ring around the word that best describes the change when ammonium nitrate
dissolves in water.
electrolysis
endothermic
exothermic
(1)
(c)
Suggest and explain why the pack is shaken after the inner bag has burst.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 4 marks)
Q7.
A student did two experiments using ammonium chloride.
(a)
In the first experiment the student heated a small amount of ammonium chloride in a test
tube.
Two reactions take place in the test tube.
Reaction 1
ammonium chloride → ammonia + hydrogen chloride
(colourless gases)
Reaction 2
ammonia + hydrogen chloride → ammonium chloride
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Plantsbrook School
(i)
Complete the sentences by crossing out the incorrect word in each box.
Reaction 1 takes place at a
high
low
temperature.
Reaction 2 takes place at a
high
low
temperature.
(1)
(ii)
Draw a ring around the word which best describes reactions 1 and 2.
combustion
displacement
oxidation
reduction
reversible
(1)
(iii)
Suggest a reason for the mineral wool at the top of the test tube.
...........................................................................................................................
...........................................................................................................................
(1)
(b)
In the second experiment the student mixed a small amount of ammonium chloride with
some water in a beaker.
The temperature of the water was measured before and after adding the ammonium
chloride.
Temperature before adding
the ammonium chloride
20°C
Temperature after adding the
ammonium chloride
16°C
Draw a ring around the word which best describes the process which takes place.
combustion
displacement
endothermic
exothermic
freezing
(1)
(Total 4 marks)
Q8.
A student heated some blue copper sulphate crystals. The crystals turned into white copper
sulphate.
Page 77
Plantsbrook School
(a)
The blue copper sulphate had to be heated to change it into white copper sulphate.
State whether the reaction was exothermic or endothermic. ....................................
Explain your answer.
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
The word equation for this reaction is shown below.
(i)
What does the symbol
tell you about this reaction?
..........................................................................................................................
(1)
(ii)
How could the student turn the white powder back to blue?
..........................................................................................................................
(1)
(Total 3 marks)
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Plantsbrook School
Section 5
Q1.
Ammonium nitrate and potassium chloride are both salts. They can be made by neutralisation
reactions.
Choose substances from the box to complete the word equations for the formation of these
two salts.
ammonia
potassium nitrate
hydrochloric acid
water
nitric acid
potassium hydroxide
ammonia + ........................................ → ammonium nitrate + water
.................................. + hydrochloric acid → potassium chloride + ..........................
(Total 3 marks)
##
A student investigated the electrolysis of copper sulfate solution.
The student’s method is shown below.
Two clean pieces of copper were weighed. One piece was used as the positive electrode
and the other piece was used as the negative electrode.
The circuit was set up as shown in the diagram.
After the electrolysis, the pieces of copper were:
• washed with distilled water
• washed with propanone (a liquid with a lower boiling point than water)
• allowed to dry
• weighed.
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Plantsbrook School
(a)
Explain why the electrode would dry faster when washed with propanone instead of water.
....................................................................................................................................
....................................................................................................................................
(1)
(b)
The student’s results are given in the table.
Positive
electrode
Negative
electrode
mass of electrode before electrolysis, in grams
16.41
15.46
mass of electrode after electrolysis, in grams
16.10
15.75
The mass of the positive electrode decreased by 0.31 g.
(i)
What is the change in mass of the negative electrode? ......................................... g
(1)
(ii)
The mass lost by the positive electrode should equal the mass gained by the negative
electrode.
Suggest two reasons why the results were not as expected.
1 ......................................................................................................................
.........................................................................................................................
2 ......................................................................................................................
.........................................................................................................................
(2)
(c)
Describe and explain how electrolysis is used to make pure copper from a lump of impure
copper.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
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....................................................................................................................................
....................................................................................................................................
(4)
(Total 8 marks)
Q3.A swimming pool was closed after two chemicals leaked into the pool.
Fire-fighters were asked to investigate the leak. They had to wear special suits.
By fairfaxcounty [CC BY-ND 2.0], via Flickr
The two chemicals that leaked were sodium hypochlorite and sulfuric acid.
The chemicals reacted together to make chlorine gas.
(a)
(i)
Which ion makes sulfuric acid acidic?
Draw a ring around the correct answer.
hydrogen ion (H+)
hydroxide ion (OH–)
sulfate ion (SO42–)
(1)
(ii)
Draw a ring around the correct answer in the box to complete the sentence.
A solution of sodium hypochlorite is alkaline.
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Plantsbrook School
4
The pH of sodium hypochlorite solution is
7
11
(1)
(iii)
Draw a ring around the correct answer in the box to complete the sentence.
combustion.
The reaction between an acid and an alkali is called
decomposition.
neutralisation.
(1)
(b)
The fire-fighters wore special suits.
Suggest why.
........................................................................................................................
........................................................................................................................
(1)
(c)
Sodium chloride solution can be electrolysed.
Sodium hypochlorite can be made using two products of the electrolysis.
Tick (
) two correct products of the electrolysis of sodium chloride solution.
Product
Tick (
)
Chlorine
Sodium
Sodium sulfate
Sodium hydroxide
(2)
(Total 6 marks)
Q4.
Titanium is a transition metal used as
pins and plates to support badly broken bones.
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Plantsbrook School
Titanium is extracted from an ore that contains the mineral titanium oxide. This oxide is converted
into titanium chloride. Titanium chloride is heated with sodium to form titanium metal. This reaction
takes place in an atmosphere of a noble gas, such as argon.
4Na(s) + TiCl4(l) → Ti(s) + 4NaCl(s)
Calculate the mass of titanium that can be extracted from 570 kg of titanium chloride.
Relative atomic masses: Cl 35.5; Ti 48.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
Mass of titanium = ............................ kg
(Total 3 marks)
Q5.
Ammonia and nitric acid are both important chemicals. Nitric acid is made from ammonia.
The charts below show substances made from ammonia and nitric acid.
Substances made from
ammonia
(a)
Substances made from
nitric acid
Use the charts to help you answer these questions.
(i)
What is the main use of both ammonia and nitric acid?
..........................................................................................................................
(1)
Page 83
Plantsbrook School
(ii)
Work out the percentage of ammonia used to make nitric acid.
Percentage = ........................ %
(1)
(iii)
100 million tonnes of ammonia are made in the world each year.
How much of this ammonia is used to make nylon?
.......................... million tonnes
(1)
(b)
The word equations below show how nitric acid is made.
1.
nitrogen + hydrogen → ammonia
2.
ammonia + oxygen → nitrogen monoxide + water
3.
nitrogen monoxide + oxygen → nitrogen dioxide
4.
nitrogen dioxide + water → nitric acid
Use the word equations to help you answer these questions.
(i)
From which two elements is ammonia made?
......................................................... and .........................................................
(1)
(ii)
Name two of the raw materials needed to make nitric acid.
......................................................... and .........................................................
(2)
(c)
A large amount of nitric acid is reacted with ammonia to make a fertiliser.
nitric acid + ammonia → fertiliser
(i)
The reaction is a neutralisation reaction.
What type of chemical must ammonia be?
...........................................................................................................................
(1)
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Plantsbrook School
(ii)
Complete the chemical name for the fertiliser made from ammonia and nitric acid.
ammonium ....................................................
(1)
(iii)
The reaction of nitric acid with ammonia is exothermic.
Name the piece of equipment you could put into the solution to prove that the reaction
is exothermic.
...........................................................................................................................
(1)
(Total 9 marks)
Q6.
Hand warmers use chemical reactions.
(a)
The table shows temperature changes for chemical reactions A, B and C.
Reaction
Starting
temperature in °C
Final temperature
in °C
Change in
temperature in °C
A
18
25
+7
B
17
.....................
+5
C
18
27
+9
What is the final temperature for reaction B? Write your answer in the table.
(1)
(b)
(i)
What name is given to reactions that heat the surroundings? ...........................
(1)
(ii)
Which reaction, A, B or C,
would be best to use in a hand warmer?
Page 85
Plantsbrook School
Reaction
Give a reason why you chose this reaction.
........................................................................................................................
........................................................................................................................
(2)
(c)
A student added water to some anhydrous copper sulfate.
The equation for the reaction is shown.
anhydrous copper sulfate
CuSO4
+
water
hydrated copper sulfate
+
5 H2O
CuSO4.5H2O
The student measured the temperature before and after the reaction.
(i)
The measurements showed that this reaction can be used for a hand warmer.
Draw a ring around the correct answer to complete the sentence.
When water is added to anhydrous copper sulfate the temperature
increases.
of the mixture
decreases.
stays the same.
(1)
(ii)
Anhydrous copper sulfate is
white.
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Plantsbrook School
What colour is seen after water is added to the anhydrous copper sulfate?
................................................................................
(1)
(iii)
What does the symbol
mean?
........................................................................................................................
(1)
(iv)
The student heated a tube containing hydrated copper sulfate.
Name the solid substance produced.
........................................................................................................................
(1)
(Total 8 marks)
Q7.
(a)
Two experiments were set up as shown.
(i)
Give two observations which would be seen only in Experiment D.
1 .......................................................................................................................
2
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Plantsbrook School
.......................................................................................................................
(2)
(ii)
Explain why in Experiment C no changes would be seen.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b)
Another electrolysis experiment used an aqueous solution of copper chloride.
(i)
What does electrolysis mean?
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Name the gas A and the deposit B.
Gas A ................................................................................................................
Deposit B ..........................................................................................................
(2)
Page 88
Plantsbrook School
(c)
Give one industrial use of electrolysis.
.....................................................................................................................................
(1)
(Total 9 marks)
Q8.
The diagram shows some magnesium ribbon burning.
(a)
Choose words from the list to complete the sentences below.
electrical
an endothermic
heat
light
an exothermic
a neutralisation
kinetic
a reduction
When magnesium burns, it transfers .........................................................................
and ............................................................................ energy to the surroundings.
We say that it is .................................................................................. reaction.
(3)
(b)
Complete the word equation for the reaction.
magnesium + __________________________
magnesium oxide
(1)
(Total 4 marks)
Page 89
Plantsbrook School
Q9.
A student investigated some instant soup.
(a)
Instant soup contains a food additive which has the formula:
NaH2PO4
Give the names of all the elements in this compound.
The periodic table on the Data Sheet may help you to answer this question.
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
The student investigated the reaction which takes place when soup powder is added to cold
water.
The student thought that the reaction might be exothermic.
(i)
What is meant by the term exothermic reaction?
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Describe an experiment that the student could do to prove that this reaction is
exothermic.
To gain full marks in this question you should write your ideas in good
English. Put them into a sensible order and use the correct scientific words.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(4)
(Total 8 marks)
Page 90
Plantsbrook School
Q10.Hydrated copper sulphate is a blue solid. When it is heated, white solid anhydrous copper sulphate
is made. This is a reversible reaction.
hydrated copper sulphate [+ heat energy]
(blue)
(a)
anhydrous copper sulphate + water
(white)
To make the forward reaction work, the hydrated copper sulphate must be heated all the
time.
What type of reaction is this?
.....................................................................................................................................
.....................................................................................................................................
(1)
(b)
Anhydrous copper sulphate can be used in a test for water. What two things will happen
when water is added to anhydrous copper sulphate?
1 ..................................................................................................................................
.....................................................................................................................................
2 ..................................................................................................................................
.....................................................................................................................................
(2)
(Total 3 marks)
Q11.
A student did two experiments using ammonium chloride.
(a)
In the first experiment the student heated a small amount of ammonium chloride in a test
tube.
Page 91
Plantsbrook School
Two reactions take place in the test tube.
Reaction 1
ammonium chloride → ammonia + hydrogen chloride
(colourless gases)
Reaction 2
ammonia + hydrogen chloride → ammonium chloride
(i)
Complete the sentences by crossing out the incorrect word in each box.
Reaction 1 takes place at a
high
low
temperature.
Reaction 2 takes place at a
high
low
temperature.
(1)
(ii)
Draw a ring around the word which best describes reactions 1 and 2.
combustion
displacement
oxidation
reduction
reversible
(1)
(iii)
Suggest a reason for the mineral wool at the top of the test tube.
...........................................................................................................................
...........................................................................................................................
(1)
Page 92
Plantsbrook School
(b)
In the second experiment the student mixed a small amount of ammonium chloride with
some water in a beaker.
The temperature of the water was measured before and after adding the ammonium
chloride.
Temperature before adding
the ammonium chloride
20°C
Temperature after adding the
ammonium chloride
16°C
Draw a ring around the word which best describes the process which takes place.
combustion
displacement
endothermic
exothermic
freezing
(1)
(Total 4 marks)
Q12.
The diagram shows how anhydrous copper sulfate can be used to test for water.
(a)
What colour change will you see when water is added to the CuSO4?
Colour changes from ............................................... to ......................................................
(1)
Page 93
Plantsbrook School
(b)
Draw a ring around the meaning of the symbol
endothermic
reversible
exothermic
(1)
(Total 2 marks)
Q13.
A student investigated the reaction of magnesium with hydrochloric acid.
(a)
A piece of magnesium was dropped into the hydrochloric acid.
Bubbles of gas were produced and the magnesium disappeared.
The reaction is exothermic.
(i)
What measurements would the student make to show that the reaction is exothermic?
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(ii)
How would these measurements show that the reaction is exothermic?
...............................................................................................................
(1)
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Plantsbrook School
The student investigated how changing the concentration of the hydrochloric acid
affects this reaction.
Each test tube contained a different concentration of hydrochloric acid.
The diagrams show the results of this experiment.
(b)
Suggest one control variable in this investigation.
........................................................................................................................
........................................................................................................................
(1)
(c)
(i)
Which test tube, A, B, C or D, contained the greatest concentration of hydrochloric
acid?
Test tube
(1)
(ii)
Why did you choose this test tube?
...............................................................................................................
...............................................................................................................
(1)
(d)
The student predicted that if the temperature of the acid was increased the reaction would
take place faster.
Tick (
) two statements in the table which explain why.
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Statement
Tick (
)
The particles move faster
The particles collide with less energy
The particles collide more often
The particles are bigger
(2)
(Total 8 marks)
Q14.A student investigated the reaction of hydrochloric acid with calcium carbonate.
(a)
The equation for the reaction is:
CaCO3(s)
(i)
+
2HCl(aq)
→
CaCl2(aq)
+
H2O(l)
+
CO2(g)
What is the name of the solution produced in the reaction?
...............................................................................................................
(1)
(ii)
What is the name of the gas produced in the reaction?
...............................................................................................................
(1)
(b)
The student measured the volume of gas produced in the reaction every half minute.
The graph shows the student’s result.
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Plantsbrook School
(b)
(i)
Use the graph to describe how the rate of this reaction changes with time.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(3)
(i)
The student repeated the investigation.
This time the temperature used was 10°C higher. All other variables were the same.
Sketch on the graph the results you would expect.
(2)
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(ii)
Explain, in terms of particles, why the change in temperature affects the rate of
reaction.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(3)
(Total 10 marks)
Q15.People sometimes use hand warmers to keep their hands warm in cold weather.
There are two types of hand warmer.
Disposable hand warmer
Reusable hand warmer
The hand warmer stays warm for
10 hours.
The hand warmer stays warm for
30 minutes.
The maximum temperature reached
is 45°C.
The maximum temperature reached
is 54°C.
The contents are:
• Iron filings (small pieces of iron)
• Water
• Salt (catalyst)
• Vermiculite (a mineral that holds water)
The contents are:
• Sodium ethanoate
• Water
• Metal disc (to start crystallisation)
Reusable hand warmers are regenerated
by putting into boiling water, then cooling.
(a)
Name the type of reaction that gives out energy in both hand warmers.
........................................................................................................................
(1)
(b)
The disposable hand warmer has a sealed airtight outer bag. To use the hand warmer the
outer bag is removed. Air gets to the iron filings inside the inner bag. The iron reacts with
oxygen from the air to produce
iron(III) oxide (Fe2O3).
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(i)
Explain why the iron in the inner bag is in small pieces and not large pieces.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(ii)
Complete and balance the symbol equation for this reaction.
........................................ + ........................................ → .......... Fe2O3
(2)
(c)
A walker wants to buy a hand warmer for use in the winter.
Evaluate the use of both types of hand warmer.
In your answer you must compare the two types of hand warmer.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(4)
(Total 9 marks)
Q16.
Magnesium reacts with dilute sulphuric acid.
magnesium + sulphuric acid → magnesium sulphate + hydrogen
A student measured the volume of hydrogen given off every 10 seconds. The results are shown on
the graph.
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Plantsbrook School
(a)
The average rate of hydrogen production in the first 10 seconds is
(60 cm3 ÷ 10 s) = 6 cm 3/s.
(i)
Calculate the average rate of production of hydrogen between 30 seconds and 50
seconds. Show clearly how you work out your answer.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
Rate ............................... cm3/s
(3)
(ii)
Explain, as fully as you can, why the average rate between 30 and 50 seconds is
different from the rate between 0 and 10 seconds.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
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Plantsbrook School
(b)
In industry, enzymes are used in both batch processes and continuous processes.
Give one reason why continuous processes are usually more profitable than batch
processes.
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 6 marks)
Q17.
Many indigestion tablets contain calcium carbonate as their only active ingredient. Calcium
carbonate neutralises some of the hydrochloric acid in the stomach.
Two different indigestion tablets, X and Y, were separately reacted with excess hydrochloric acid.
The volume of gas given off in each reaction was measured every minute.
The results are shown in the graph.
(i)
Which tablet, X or Y, contained most calcium carbonate? ..............................
Explain the reason for your answer.
.....................................................................................................................................
.....................................................................................................................................
(1)
(ii)
Which tablet, X or Y, reacted
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faster with hydrochloric acid?...........................
Plantsbrook School
Explain the reason for your answer.
.....................................................................................................................................
.....................................................................................................................................
(1)
(iii)
Explain the shape of the graph for tablet X between 3 and 5 minutes.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(1)
(Total 3 marks)
Q18.
Hydrogen peroxide (H2O2) contains the same elements as water (H2O).
(a)
Name the hazard symbol shown by using the correct word from the box.
corrosive
flammable
oxidising
toxic
(1)
(b)
Hydrogen peroxide decomposes in the presence of a catalyst.
2H2O2(aq) → 2H2O(l) + O2(g)
(i)
Complete the word equation for this chemical reaction.
hydrogen peroxide → water + ................................
(1)
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Plantsbrook School
(ii)
What does a catalyst do to a chemical reaction?
...........................................................................................................................
...........................................................................................................................
(1)
(Total 3 marks)
Q19.
A student investigated the rate of reaction between marble and hydrochloric acid.
The student used an excess of marble.
The reaction can be represented by this equation:
CaCO3(s)
+
2HCl(aq)
→
CaCl2(aq)
+
H2O(l)
+
CO2(g)
The student used the apparatus shown in the diagram.
The student measured the mass of the flask and contents for ten minutes.
The results are shown on the graph. Use the graph to answer the questions.
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Plantsbrook School
(a)
(i)
Complete the graph by drawing a line of best fit.
(1)
(ii)
Use the graph to find the mass of the flask and contents after 1.8 minutes.
................................. grams
(1)
(iii)
The rate of reaction can be measured by the steepness of the graph line.
Describe, as fully as you can, how the rate of reaction changes with time in this
experiment.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(b)
The mass of the flask and contents decreased during the experiment.
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Use the equation for this reaction to help you explain why.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(2)
(c)
A balance is used to measure the mass of the apparatus.
(i)
Which balance, A, B, or C, has the highest resolution?
Balance A
Balance B
Balance C
The balance with the highest resolution is balance
(1)
(ii)
The balance used for this experiment should have a high resolution.
Explain why.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
(2)
(d)
The student repeated the experiment using powdered marble instead of marble chips.
The rate of reaction between the marble and hydrochloric acid particles was much faster with
the powder.
Explain why.
........................................................................................................................
........................................................................................................................
........................................................................................................................
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Plantsbrook School
........................................................................................................................
(2)
(Total 11 marks)
Q20.
Sodium thiosulfate solution reacts with hydrochloric acid. As the reaction takes place the
solution slowly turns cloudy.
The diagram shows a method of measuring the rate of this reaction.
A student used this method to investigate how changing the concentration of the sodium thiosulfate
solution affects the rate of this reaction.
The student used different concentrations of sodium thiosulfate solution. All the other variables
were kept the same.
The results are shown on the graph below.
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Plantsbrook School
(a)
(i)
Draw a line of best fit on the graph.
(1)
(ii)
Suggest two reasons why all of the points do not lie on the line of best fit.
1 ........................................................................................................................
...........................................................................................................................
2 ........................................................................................................................
...........................................................................................................................
(2)
(b)
(i)
In a conclusion to the investigation the student stated that:
‘The rate of this reaction is directly proportional to the concentration of the sodium
thiosulfate solution.’
How does the graph support this conclusion?
...........................................................................................................................
...........................................................................................................................
(1)
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Plantsbrook School
(ii)
Explain, in terms of particles, why the rate of reaction increases when the
concentration of sodium thiosulfate is increased.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 6 marks)
Q21.
(a)
The symbol equation for the decomposition of hydrogen peroxide is:
2H2O2
→
2H2O + O2
Complete the word equation for the decomposition of hydrogen peroxide.
Hydrogen peroxide → .................................... + ....................................
(1)
(b)
A student did an experiment to see how quickly hydrogen peroxide decomposes.
The student used the apparatus shown below to measure the volume of oxygen.
(i)
Draw a straight line of best fit to complete the graph.
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Plantsbrook School
(1)
(ii)
Draw a circle around the anomalous point on the graph.
(1)
(iii)
What is the volume of oxygen given off after 15 seconds?
......................... cm3
(1)
(iv)
How did the volume of oxygen change between 0 and 25 seconds?
...............................................................................................................
(1)
(c)
The student wanted to make the reaction faster.
Draw a ring around the correct answer to complete each sentence.
higher.
(i)
To make the reaction faster, the temperature should be
lower.
the same.
(1)
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Plantsbrook School
more dilute.
(ii)
To make the reaction faster, the hydrogen peroxide should be
more concentrated.
the same.
(1)
(d)
The diagram represents the bonding in oxygen.
O=O
Draw a ring around the correct answer to complete each sentence.
share
(i)
When two oxygen atoms bond, the atoms
transfer
electrons.
delocalise
(1)
ionic
(ii)
The oxygen atoms are joined by
metallic
bonds.
covalent
(1)
simple molecules.
(iii)
Oxygen is made of
a giant lattice.
macromolecules.
(1)
(e)
When hydrogen peroxide decomposes water is produced.
Which two statements in the table explain why water is a liquid at room temperature?
Tick (
) the two statements.
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Plantsbrook School
Statement
Tick (
)
Water has a boiling point of 100 °C.
Water is made of ions.
Water has a melting point lower than room
temperature.
Water has a giant covalent structure.
(2)
(Total 12 marks)
Q22.
Read the information about car engines.
Burning petrol in air is an exothermic reaction. This reaction is used in car engines.
When petrol burns it produces harmful substances such as nitrogen oxides and
carbon monoxide.
A catalytic converter stops these harmful substances being released into the air.
(a)
Draw a ring around the correct answer to complete each sentence.
decrease.
(i)
The exothermic reaction makes the temperature of the engine
increase.
stay the same.
(1)
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Plantsbrook School
energy is taken in from the surroundings.
(ii)
This is because during exothermic reactions
energy is given out to the surroundings.
there is no energy change.
(1)
(b)
The diagram shows a catalytic converter which removes harmful substances.
The catalytic converter has two parts, A and B, which contain different catalysts.
(i)
2NO
→
The equation for the reaction that takes place in part A is:
N2
+
O2
Which one of the substances shown in the equation is a compound?
Give the formula of this compound.
...............................................................................................................
(1)
(ii)
2CO
+
The equation for the reaction that takes place in part B is:
O2
→
2CO2
Why is it important to stop carbon monoxide (CO) from being released into the air?
...............................................................................................................
...............................................................................................................
(1)
(c)
The table lists some statements about catalysts. Only two statements are correct.
Tick (
) the two correct statements.
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Plantsbrook School
Statement
Tick (
)
A catalyst can speed up a chemical reaction.
A catalyst is used up in a chemical reaction.
Different reactions need different catalysts.
A catalyst does not change the rate of a chemical reaction.
(2)
(d)
Modern catalytic converters contain nanosized particles of catalyst.
Less catalyst is needed when nanosized catalyst particles are used.
(i)
Complete the sentence.
The size of nanosized particles is ........................................ than normal sized
particles.
(1)
(ii)
The catalysts contain platinum.
Suggest why a manufacturer of catalytic converters would want to use less catalyst.
...............................................................................................................
...............................................................................................................
(1)
(Total 8 marks)
Q23.
Metal is bent and shaped to make a car body.
The diagram below represents how atoms are arranged in a metal.
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Which two statements in the table best explain why the metal can be bent and shaped?
Tick (
) the two statements.
Statement
Tick
( )
The atoms are in layers.
The metal is shiny.
The atoms can slide over each other.
All the atoms are linked by strong
covalent bonds.
(2)
(Total 2 marks)
Q24.
This picture shows a sword. The sword is about 3400 years old. It is made of an alloy called
bronze.
Photograph © O.Louis Mazzatenta / Getty Images
Bronze is made from copper and tin.
Bronze made better swords than pure copper. This is because bronze is harder than pure copper.
(a)
Draw a ring around the correct answer to complete the sentence.
metals.
An alloy is a mixture of
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Plantsbrook School
molecules.
non-metals.
(1)
(b)
Pure copper can be quite easily bent out of shape.
Which two statements in the table explain why copper can be bent?
Tick ( ) two boxes.
Statements
Tick ( )
Copper atoms are arranged in layers.
Copper atoms are joined by strong covalent bonds.
Copper atoms can slide over each other.
Copper is made of small molecules.
(2)
(c)
Which one statement in the table explains why bronze is harder than pure copper?
Tick ( ) one box.
Statements
Tick ( )
Copper and tin atoms are the same size.
The layers of atoms are distorted in bronze.
The copper and tin atoms are joined by strong
covalent bonds in bronze.
(1)
(Total 4 marks)
Q25.
The diagrams show five different atoms, A, B, C, D and E.
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Plantsbrook School
(a)
Which atom, A, B, C, D or E:
(i) has an atomic number (proton number) of 3
Atom
(1)
Atom
(ii) has a mass number of 2
(1)
(iii)
Atom
is in Group 2 of the periodic table?
(1)
(b)
Atom
Which two atoms from A, B, C, D and E are isotopes of the same element?
and Atom
(1)
(c)
Which particle in an atom has a
Page 116negative charge? .......................................
Plantsbrook School
(1)
(Total 5 marks)
Q26.
(a)
(i)
The diagram shows part of the ionic lattice of a sodium chloride crystal.
Complete the spaces in the table to give information about both of the ions in this
lattice.
Name of ion
Charge
.....................................................
.....................................................
.....................................................
.....................................................
(2)
(ii)
When it is solid, sodium chloride will not conduct electricity. However, molten sodium
chloride will conduct electricity. Explain this difference.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(iii)
Complete the sentence.
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Plantsbrook School
Sodium chloride conducts electricity when it is molten and when it is
..........................................................................................................................
(1)
(b)
The symbol for a calcium atom can be shown like this:
(i)
What is the mass number of this atom?
..........................................................................................................................
(1)
(ii)
What information is given by the mass number?
..........................................................................................................................
..........................................................................................................................
(1)
(c)
Calcium burns in oxygen with a brick-red flame. The product is a white solid. It is calcium
oxide and its formula is CaO.
(i)
Balance the chemical equation for the reaction.
Ca(s) + O2(g) → CaO(s)
(1)
(ii)
Describe, in terms of electrons, what happens to a calcium atom when it becomes a
calcium ion.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(Total 10 marks)
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Plantsbrook School
Q27.
(a)
The diagrams represent the atomic structures of two gases, hydrogen and helium.
Hydrogen gas is made up of diatomic molecules (molecules with two atoms).
Helium gas exists as single atoms.
(i)
How is a molecule of hydrogen formed from two hydrogen atoms?
(You may use a diagram as part of your answer)
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Why does helium exist only as single atoms?
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b)
Hydrogen combines with carbon to form methane.
Each molecule contains four hydrogen atoms strongly bonded to a carbon atom.
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Explain why methane has a low boiling point.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 6 marks)
Q28.
Use the Formulae of Some Common Ions table on the Data Sheet to help you to answer this
question.
Acids react with alkalis to form salts and water.
Complete the table below by writing in the name and formula of the salt formed in each reaction.
The first one has been done for you.
Acid
Alkali
Salt
Formula of salt
Hydrochloric acid
Sodium hydroxide
Sodium chloride
NaCl
Nitric acid
Sodium hydroxide
Sulphuric acid
Potassium hydroxide
(Total 4 marks)
Q29.
Two isotopes of hydrogen are hydrogen-1 (
) and hydrogen-2 (
The diagrams represent atoms of hydrogen-1 and hydrogen-2.
(a)
Use the correct words from the box to complete the sentences.
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).
Plantsbrook School
enp
ler
euo
c tr t
t oo
r nn
os s
n
s
(i)
The positive particles,
, in the nucleus of atoms are called
............................................................................ .
(1)
(ii)
The particles with no charge, ● , in the nucleus of atoms are called
............................................................................ .
(1)
(b)
The diagrams show two different types of water molecule.
Draw a ring around the correct answer to complete the sentence.
heavier than
Molecule A is lighter than
molecule B.
the same mass as
Explain your answer.
........................................................................................................................
........................................................................................................................
(2)
(Total 4 marks)
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Plantsbrook School
Q30.
This question is about giant structures. Diamond, graphite and silicon dioxide all have giant
structures.
(a)
The diagrams show the structures of these three substances.
Draw a line from each structure to its name.
(2)
(b)
Complete the sentences using words from the box.
covalent
four
hard
ionic
shiny
soft
three
two
(i)
Diamond, graphite and silicon dioxide have high melting points because all the
atoms in their structures are joined by strong ............................................... bonds.
(1)
(ii)
In diamond each atom is joined to ............................................... other atoms.
(1)
(iii)
Diamond can be used to make cutting tools because it has a rigid structure which
makes it very
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................................................
Plantsbrook School
(1)
(iv)
In graphite each atom is joined to ............................................... other atoms.
(1)
(v)
Graphite can be used to make pencils because it has a structure which makes it
................................................
(1)
(c)
When a diamond is heated to a high temperature and then placed in pure oxygen it burns.
Carbon dioxide is the only product.
Name the element in diamond. ...................................................................................
(1)
(Total 8 marks)
Q31.
(a)
Write down the symbols for
lithium ................................................................................
fluorine ...............................................................................
(2)
(b)
The electronic structure of a lithium atom can be shown like this:
In a similar way, complete this diagram to show the electronic structure of a fluorine atom.
(1)
(c)
A lithium atom can lose one
electron to form a lithium ion which can be
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Plantsbrook School
written (2)
A fluorine atom can gain one electron to form a fluoride ion.
+
Choose from the list the correct way to write the fluoride ion.
(2,6)+
(2,7)+
(2,7)-
(2,8)+
(2,8)–
Answer ..........................................
(2)
(Total 5 marks)
Q32.
Iron ore contains iron oxide.
(i)
Calculate the relative formula mass of iron oxide, Fe2O3.
Relative atomic masses: O = 16; Fe = 56.
.....................................................................................................................................
.....................................................................................................................................
Answer = ................................................
(2)
(ii)
Calculate the percentage by mass of iron in iron oxide.
.....................................................................................................................................
Percentage of iron = .......................................... %
(2)
(iii)
Calculate the mass of iron that could be extracted from 1000 kg of iron oxide.
Use your answer to part (c) (ii) to help you with this calculation.
.....................................................................................................................................
Mass of iron = ................................................... kg
(1)
(Total 5 marks)
Q33.
The extract below was taken from a leaflet on the uses of platinum. One of the uses described
was in making electrodes for spark plugs in car engines. The spark plug produces the spark which
ignites the fuel in the engine.
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Plantsbrook School
Spark Plugs
The electrodes in a spark plug have to conduct electricity very well. Since they project
into the combustion chamber of the engine, they must also be able to withstand
extremely high temperatures in a very corrosive atmosphere.
Nickel-based plugs have been produced for many years. They only last a fairly short
time. As the electrodes wear, combustion becomes less efficient and the petrol is not
burnt completely.
Platinum and other precious metals can now be used in spark plugs. These last much
longer and are more efficient. This can help to reduce air pollution.
The table below gives some information about platinum and nickel.
MELTING
POINT
(° C)
BOILING
POINT
(° C)
POSITION IN
REACTIVITY
SERIES
COST
(£/kg)
nickel
1455
2920
Higher than gold
2.5
platinum
1769
4107
below gold
6110
(a)
Compare nickel and platinum for use in making the electrodes in spark plugs.
A good answer should give advantages and disadvantages of each metal linking these to the
properties of the metals. Marks will be given for the way in which you organise your answer.
You will need a sheet of lined paper.
(8)
(b)
(i)
Describe the structure and bonding in metals.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)Page 125
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(ii)
Explain why metals such as nickel and platinum are good conductors of electricity.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 13 marks)
Q34.The electrolysis of sodium chloride solution is an industrial process.
The diagram shows the apparatus used in a school experiment.
(a)
One of the products of the electrolysis of sodium chloride solution is hydrogen.
(i)
Why do hydrogen ions move to the negative electrode?
...............................................................................................................
...............................................................................................................
(1)
(ii)
How does a hydrogen ion change into a hydrogen atom?
...............................................................................................................
...............................................................................................................
(1)
(b)
Hydrogen is used to make ammonia (NH3).
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Plantsbrook School
Complete the diagram to show the bonding in ammonia.
Use dots (●) and crosses (x) to show electrons.
Show only outer shell electrons.
(2)
(c)
The table shows the ions in sodium chloride solution.
Positive ions
Negative ions
hydrogen
chloride
sodium
hydroxide
In industry, some of the waste from the electrolysis of sodium chloride solution is alkaline
and has to be neutralised.
(i)
Which ion makes the waste alkaline?
...............................................................................................................
(1)
(ii)
This waste must be neutralised.
Write the ionic equation for the neutralisation reaction.
...............................................................................................................
(1)
(d)
In this question you will be assessed on using good English, organising information clearly
and using specialist terms where appropriate.
The electrolysis of sodium chloride solution also produces chlorine and sodium hydroxide.
In industry, the electrolysis of sodium chloride solution can be done in several types of
electrolysis cell.
Some information about two different types of electrolysis cell is given below.
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Plantsbrook School
Mercury cell
Membrane cell
Cost of construction
Expensive
Relatively cheap
Additional substances used
Mercury, which is recycled.
Mercury is toxic so any traces
of mercury must be removed
from the waste
Membrane, which is made
of a polymer. The
membrane must be
replaced every 3 years.
Amount of electricity used for
each tonne of chlorine
3400
produced in kWh
2950
Quality of chlorine produced
Pure
Needs to be liquefied and
distilled to make it pure.
Quality of sodium hydroxide
solution produced
50% concentration. Steam is
used to concentrate the
sodium hydroxide solution
produced.
30% concentration. Steam
is used to concentrate the
sodium hydroxide solution
produced.
Use the information and your knowledge and understanding to compare the environmental
and economic advantages and disadvantages of these two types of electrolysis cell.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
(6)
(Total 12 marks)
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Plantsbrook School
Q35.The electrolysis of sodium chloride solution is an industrial process.
The diagram shows the apparatus used in a school experiment.
(a)
One of the products of the electrolysis of sodium chloride solution is hydrogen.
(i)
Why do hydrogen ions move to the negative electrode?
...............................................................................................................
...............................................................................................................
(1)
(ii)
How does a hydrogen ion change into a hydrogen atom?
...............................................................................................................
...............................................................................................................
(1)
(b)
Hydrogen is used to make ammonia (NH3).
Complete the diagram to show the bonding in ammonia.
Use dots (●) and crosses (x) to show electrons.
Show only outer shell electrons.
(2)
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Plantsbrook School
(c)
The table shows the ions in sodium chloride solution.
Positive ions
Negative ions
hydrogen
chloride
sodium
hydroxide
In industry, some of the waste from the electrolysis of sodium chloride solution is alkaline
and has to be neutralised.
(i)
Which ion makes the waste alkaline?
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(1)
(ii)
This waste must be neutralised.
Write the ionic equation for the neutralisation reaction.
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(1)
(d)
In this question you will be assessed on using good English, organising information clearly
and using specialist terms where appropriate.
The electrolysis of sodium chloride solution also produces chlorine and sodium hydroxide.
In industry, the electrolysis of sodium chloride solution can be done in several types of
electrolysis cell.
Some information about two different types of electrolysis cell is given below.
Mercury cell
Membrane cell
Cost of construction
Expensive
Relatively cheap
Additional substances used
Mercury, which is recycled.
Mercury is toxic so any traces
of mercury must be removed
from the waste
Membrane, which is made
of a polymer. The
membrane must be
replaced every 3 years.
Amount of electricity used for
each tonne of chlorine
3400
produced in kWh
2950
Quality of chlorine produced
Pure
Needs to be liquefied and
distilled to make it pure.
Quality of sodium hydroxide
solution produced
50% concentration. Steam is
used to concentrate the
sodium hydroxide solution
produced.
30% concentration. Steam
is used to concentrate the
sodium hydroxide solution
produced.
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Plantsbrook School
Use the information and your knowledge and understanding to compare the environmental
and economic advantages and disadvantages of these two types of electrolysis cell.
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(6)
(Total 12 marks)
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