CFE Chemistry
Unit 1 Chemical Changes & Structure
S3 Chemistry
Unit 1
Chemical Changes & Structure
Name
-1-
CFE Chemistry
Lesson 1
Unit 1 Chemical Changes & Structure
Chemical Reactions
I can state the 4 signs of a chemical reaction
I can explain what is an element, compound and mixture
Chemistry is the study of chemical substances - what things are
made of, how they react with each other and how one substance can
be changed into another.
Pupil Experiment
Aim: To identify signs of a chemical reaction.
Method: The teacher will give you instructions for a series of
experiments involving chemical reactions
Results: Record some signs of a chemical reaction below:
1.
2.
3.
4.
-2-
CFE Chemistry
Unit 1 Chemical Changes & Structure
Lesson 2
Reaction rates
I can name three things which can speed up a chemical reaction
I can draw and interpret graphs to compare reaction rates
Chemical reactions can occur at different speeds or rates.
Consider the following chemical reactions and complete the
table.
Decide if they are slow, medium or fast and give
another example. Does your partner agree?:
Reaction
Speed or rate
Another Example
Iron nail rusting
Bomb Explosion
Making Toast
This series of experiments is designed so that you can identify whether
the speed or rate of a reaction can be altered:
Pupil Experiment 1 - Concentration
Aim: To identify whether speed of reaction can be changed
by increasing the concentration of acid
Method: The teacher will give you instructions for an experiment
Results: Record your results in the table provided and plot a line
graph of volume of gas produced vs time taken, with two lines – one
for the most concentrated acid (2M) and also least concentrated acid
(0.5M)
Conclusion (what did you find out):
-3-
CFE Chemistry
Unit 1 Chemical Changes & Structure
Pupil Experiment 2 – Temperature
Aim:
To identify whether speed of reaction can be changed by
increasing the temperature of reaction
Method: The teacher will give you instructions for an experiment
Results: Record your results in the table provided and plot a line graph
of temperature vs time taken using points at 40oC, 50oC and 60oC
Conclusion (what did you find out):
Pupil Experiment 3 – Particle Size
Aim: To identify whether speed of reaction can be changed
by changing the particle size
Method: The teacher will give you instructions for an experiment
Results: Record your results in the table provided and plot a line graph
with volume of bubbles produced vs time taken with two lines – one for
small particle size (crushed marble chips) and also large marble chips.
Conclusion (what did you find out):
Complete the following sentence:
From this series of experiments I was able to identify that:
-4-
CFE Chemistry
Lesson 3
Unit 1 Chemical Changes & Structure
Inside the atom
I can name the 3 subatomic particles, explain where they are
found in an atom and state their charge
All elements are made up of small particles called ATOMS, with each
element made from its own unique type of atom. However, all atoms have
a similar atomic structure.
Investigating atomic structure
Your teacher will carry out a co-operative group exercise on
the subatomic particles that make up the atom.
Complete the diagram below at end of exercise by adding appropriate
labels.
Even though atoms have these sub-atomic particles they are mostly
composed of empty space!!
Imagine we enlarge an atom to the size of a football pitch. The electrons
would orbit through the goal posts, the nucleus would be the size of a
tennis ball in the centre and the rest of the pitch would be empty space!
Particle
Charge
Electron
Neutron
Proton
-5-
Where is it found in atom
CFE Chemistry
Unit 1 Chemical Changes & Structure
Investigating atomic structure
Use the atom models to help with this investigation. Using the
information in the table - make each of the following atoms and then
complete the drawing in the last column of the table. The first one has
been done for you.
Element
Protons
Neutrons
Electrons
Helium
2
2
2
Atom Drawing
Electrons
Protons
neutrons
Hydrogen
1
0
1
Carbon
6
6
6
Boron
5
6
5
Can you explain why atoms are electrically neutral from table above?
(clue: look at the symbols on the atom model)
Did you notice that the electrons are in layers? We will discuss this
further in electron arrangements.
-6-
CFE Chemistry
Lesson 4
Unit 1 Chemical Changes & Structure
Atomic & Mass Number
I can explain what an atomic number and a mass number are in
an atom
I can state the mass of subatomic particles
I can explain why atoms are electrically neutral
Look at any periodic table in the chemistry Data Booklet. Notice that
each element has a number above it - this is its unique ATOMIC
NUMBER. The atomic number used to be called the proton number, as it
tells us the number of protons in the nucleus.
Atoms are electrically neutral because the number of protons (+ve
charge) is the same as the number of electrons (-ve charge).
Investigating atomic number
Using your knowledge of atoms complete the table below:
Atomic
Element
Symbol
Protons
Electrons
Number
O
12
Lithium
Be
14
Fluorine
The mass of an atom is very small, at 0.000000000000000000000000167g.
This means that a single crystal of an element has millions of atoms!
Atoms are so small that they are not measured in grams they are
measured in atomic mass units (amu).
-7-
CFE Chemistry
Unit 1 Chemical Changes & Structure
Atomic & Mass Number
Atomic Mass
Complete the table.
Particle
Charge
Approximate
Where is it
mass (a.m.u.)
found in atom
Electron
Neutron
Proton
Did you notice that an electron has a mass of almost zero?
This means that 99.9% of the mass of an atom is located in the nucleus.
The number of protons + neutrons in an atom is known as the MASS
NUMBER.
Chemists use a special system for writing the mass number, atomic
number and symbol for an element. It is called nuclide notation:
Mass no.
Atomic No.
X
The mass number is given on top with the
atomic number written underneath. The atomic
number is always the smaller number!
-8-
CFE Chemistry
Unit 1 Chemical Changes & Structure
Atomic & Mass Number
Can you work out the number of protons, electrons and neutrons in an
atom?
Complete the table below using the information provided.
Nucleotide
Protons
Neutrons
23 Na
11
12 C
6
16 O
8
35 Cl
17
4 He
2
1.
2.
What is meant by the atomic number?
What is meant by the mass number?
-9-
Electrons
CFE Chemistry
Lesson 5
Unit 1 Chemical Changes & Structure
Electron Arrangement
I can state and draw the electron arrangements for the first
20 elements
I can state that elements with the same outer electrons are
grouped together.
How are the electrons arranged in an atom?
Each element has a unique number of electrons orbiting the nucleus of its
atoms. This number is the same as its atomic number (number of protons
in the nucleus).
How are these electrons arranged around the nucleus?
1st energy level
2nd energy level
3rd energy level
There is a maximum of 2 electrons in the first shell. Further shells can
hold 8.
The electrons are organised in these “shells” or layers.
The electron arrangement for this atom is written 2,8,1 – it can also be
written 2)8)1.
The electron arrangements for some atoms can be found on page 6 of the
Data Booklet.
- 10 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Electron Arrangements
Investigating electron arrangement
Draw the electron arrangement for the first 10 elements in
your jotter. Your teacher may let you use the atom model.
Complete the following diagram to briefly describe how the electrons are
arranged in an atom.
__________ atom
first _____ level
11+
______ ______ level
third ______ level
The number of electrons in the last or furthest away layer is called the
number of outer electrons.
Use page 6 of the Data Booklet:
1. To which group do lithium, sodium and potassium belong? ____
2. How many outer electrons do the group 1 elements have? ___
3. How many outer electrons do the group 4 elements have? ___
4. How many outer electrons do the group 7 elements have? ___
- 11 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Electron Arrangements
How does the electron arrangement affect the chemical properties of
each element?
Your teacher will demonstrate some reactions of alkali metals
(group 1 elements). Consider the following questions:
1.
What is the electron arrangement of the sodium atom?
2.
What do you notice about all the group 1 electron arrangements?
3.
How is group 0 different from other groups with respect to outer
electrons?
4.
Can you describe a general rule that links the number of electrons
to the group number?
5.
Can you explain how the outer number of electrons or group number
affects the way in which an atom reacts and so affects its chemical
properties?
- 12 -
CFE Chemistry
Lesson 6
Unit 1 Chemical Changes & Structure
Investigating bonding
I can state that compounds are held together by bonds
I can name the two different types of bonding when elements
join together, which affect the properties of their compounds
Atoms join together and form bonds between them to make molecules.
Pupil Experiment - Investigating bonding
Aim:
To identify whether compounds which either contain 2
non-metals or metals and non-metals behave differently due
to their bonding
Method: Discuss a method with your teacher
Results: Record your results in the table below:
Substance
Contains metal /
Conducts electricity
Melting point
non metals?
Solid
High / low
Solution
Sodium Chloride
Gelatin
Wax
Glucose
Copper Chloride
Potassium Bromide
Name two differences between the properties of compounds containing
either 2 non-metals or a metal and a non-metal.
1.
2.
- 13 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Investigating bonding
How do non-metal atoms bond together?
Non-metal atoms like hydrogen and oxygen join to form water by bonds
called covalent bonds.
What is a covalent bond?
Negative
Electron
Positive
nucleus
e
e
+
H
+
H
Area
Areaof
ofattraction.
attraction
Both
positive
Both positive nuclei
nuclei are
attracted
to
the
shared
pair of
attracted to shared
pair of
negatively
negatively charged
charged electrons
electrons
A covalent bond is the attraction of two nuclei for a shared pair of
electrons. In covalent bonding electrons are shared between atoms.
As well as having it’s own name, each substance can also be
represented by a chemical formula. Here is water:
Key:
Water
Formula: H2O
Ammonia
Formula:
Methane
Formula:
Nitrogen
Oxygen
- 14 -
Carbon
Hydrogen
CFE Chemistry
Unit 1 Chemical Changes & Structure
Investigating bonding
Ionic bonding Instead of sharing electrons, atoms can transfer
electrons. This is called ionic bonding, and occurs when metals bond with
non-metals.
Na (2,8,1)
Cl (2,8,7)
Na+ (2,8)
Cl-(2,8,8)
Remember atoms are trying to achieve full outer electron shell (e.g. like
Neon 2,8) when they bond, so they can get a stable electron arrangement
like a noble gas!
Ionic bonding involves the transfer of outer electrons.
 Sodium atom 2,8,1
o Loses an electron to chlorine to get to a full outer electron
shell
o Electron arrangement is now 2,8
 Chlorine atom 2,8,7
o Gains an electron from sodium to get to a full outer electron
shell
o Electron arrangement now 2,8,8
Complete the following:
Atoms can be joined by __________ or _______ bonds.
__________ bonding involves the sharing of electrons. Ionic bonding
involves the
of
electrons.
Non-metals
are
joined
by
__________ bonds. Metals are joined to non-metals by _______ bonds
- 15 -
CFE Chemistry
Lesson 7
Unit 1 Chemical Changes & Structure
Covalent Bonding and Formulae
I can show covalent bonding as a sharing of electrons by
drawing non-metal atoms joined together in a molecule
I can work out the chemical formula given the number of atoms
of each element in a molecule
Can you build & write the chemical formula for the
following substances? (colours on PowerPoint slide)
Chemical
Diagram
Chemical Formula
ethanol
(alcohol)
C2H6O
propane
(camping gas)
vinegar
acetone
(nail polish remover)
Ethylene glycol
(antifreeze)
aspirin
- 16 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Covalent Bonding and Formulae
Drawing Molecules
Use molecular models to build the molecules on the following
table. There cannot be any holes left in the atoms. Draw the
molecules into the table under 2-D structural formula. Afterward your
teacher will tell you the names of these shapes of molecules.
Compound
2-D structural
formula
Chemical formula
shape
Hydrogen
chloride
Carbon
chloride
Hydrogen
oxide
Carbon
hydride
What exactly do atoms do to form a bond?
Here are simplified electron arrangement diagrams of a hydrogen atom
and a chlorine atom. (Only the outer electrons are shown in fluorine).
H
1
F
2,7
Can you see a way that both of these atoms can have full, stable electron
arrangements? Draw it in your jotter.
- 17 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Covalent Bonding and Formulae
Non-metal atoms achieve a full, stable electron arrangement by
__________ electrons with each other. This sharing of electrons is
what makes a __________ bond.
More Examples:
Draw Electron sharing diagrams (with outer electrons only) for
the compounds of:
a)
Hydrogen and chlorine
b)
Hydrogen and oxygen
c)
Nitrogen and hydrogen
d)
Carbon and hydrogen
- 18 -
CFE Chemistry
Lesson 8
Unit 1 Chemical Changes & Structure
Ionic bonding
I can explain that an ionic bond is caused by electrostatic
attraction between ions (charged particles)
Ionic compounds are formed between metal and non-metal elements.
When we make an ionic compound we transfer electrons.
Na 2,8,1
Cl 2,8,7
Na+ (2,8)
Cl– (2,8,8)
These charged particles are called ions.
Ions: Atoms that have a charge because they have gained or lost
electrons.
Atoms form ions by __________ or __________ electrons. Electrons
have a __________ charge. Metal atoms always __________electrons
and so always form __________ charged ions. Non-metal atoms form
ions with __________ charges because they always __________
electrons. An atom will gain or lose as many __________ as it needs to
get a __________ outer shell.
Once the ions are formed they are held together in a lattice by bonds
caused by electrostatic attraction between positive and negative ions.
Na+
Cl-
Ionic Bond: The electrostatic attraction between positive and
negative ions.
- 19 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Bonding Revision
1.
Draw a table and use it to classify these properties as
belonging to ionic or covalent substances
Low melting and boiling
points
Form ions when dissolved or
molten
Usually exists as liquids
or gases at room
temperature
Never conduct electricity
High melting and boiling
points
Conduct electricity when
molten or dissolved
2.
Usually exists as
solids
at room temperature
Work out if these compounds are ionic or covalent.
Name
Formula
Nitrogen
N2
Bonding
Name
Formula
Carbon
CO2
dioxide
Calcium
CaO
Oxide
Lithium
Li2S
sulphide
Iodine
I2
Methane
CH4
Aluminium
Al2O3
Sodium
Na2S
oxide
sulphide
- 20 -
Bonding
CFE Chemistry
Unit 1 Chemical Changes & Structure
Lesson 9 Formula of Compounds
I can state the chemical formulae of two element compounds.
I can explain what the endings –ide, -ate and –ite mean
Extension: I can work out chemical formulae using valencies
(SVSS)
Can you work out the formula and names of compounds?
Compounds are made when different elements join together, using either
covalent or ionic bonds.
These compounds get their names from the
elements that make them up. The ending of the compound gives us a clue
to the elements present.
Write the definitions for –ide, -ite and – ate, then complete
the following table:
-ide ending means
-ite or –ate ending means
Compound
Elements present
caesium bromide
potassium chloride
magnesium phosphate
boron fluoride
aluminium oxide
sulfur oxide
potassium sulfate
calcium sulfite
- 21 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Formula of Compounds
In the previous table we identified the elements present, but how do
we work out the actual formula?
For some elements, including the noble gases, the formula is
just the element symbol. They are said to be monatomic (one
–atomed). Complete the table:
He
Ne
Ar
Kr
Xe
Rn
Symbol
Element
He
Ne
Ar
Kr
Xe
Rn
There are 7 non-metal elements that exist as diatomic molecules (2
atoms joined together).
H H
Element
Chemical Formula
hydrogen
N
N
Cl
Br
Br
I
I
Nitrogen
Oxygen
O O
Cl
Flourine
Chlorine
F
F
Bromine
Iodine
The diatomic elements all have names ending in -_____ or -_____
- 22 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
In most compounds we have to use the combining power of an element or
valency to work out the chemical formula.
Valency – the combining power of an atom
Different elements have different valencies depending on their position
in the periodic table.
Group No
1
2
3
4
5
6
7
Valency
1
2
3
4
3
2
1
1
2
3
4
5
6
7
0
H
He
Li
Be
B
C
N
O
F
Ne
Na
Mg
Al
Si
P
S
Cl
Ar
K
Ca
Ga
Ge
As
Se
Br
Kr
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Chemical Formulae -SVSS
To work out the formula we use 3 stages. S- symbol, V- valency, S- swap
over, S- simplify
e.g. silicon oxide
S - Symbols:
Si
O
V - Valency
4
2
S – Swap over valencies
Si2
O4
S – Simplify
Si
O2
• Formula
SiO2
- 23 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Formula of Compounds
Use the valency method to write the formula for each of the
following.
Answer in your jotter.
(a)
hydrogen fluoride
(f)
hydrogen chloride
(b)
hydrogen sulphide
(g)
phosphorous hydride
(c)
nitrogen chloride
(h)
nitrogen fluoride
(d)
phosphorous chloride
(i)
silicon hydride
(e)
carbon oxide
(j)
silicon oxide
Meaningful names
There are some covalent compounds with names which have prefixes
which can be used to write the formula. The valency method should not
be used when writing the formula for these compounds.
Complete the table below.
Prefix
Meaning
Compound
mono
carbon monoxide
di
sulfur dioxide
tri
sulfur trioxide
tetra
carbon tetrachloride
- 24 -
Formula
CFE Chemistry
Lesson 10
Unit 1 Chemical Changes & Structure
Chemical Equations
I can write a word equation for a chemical reaction
I can write simple symbol equations from word equations
Can you write a balanced chemical equation?
Word equations
A word equation is a statement showing the reactants on the left
separated by an arrow from the products on the right. For example, zinc
combines with oxygen to form zinc oxide. The word equation for this is:
zinc + oxygen
zinc oxide
Complete word equations for the following reactions:
(a)
Hydrogen joins up with oxygen to form water.
(b)
Carbon dioxide and water are produced when methane reacts with
oxygen.
(c)
Iron is formed when iron oxide is heated with carbon monoxide.
Carbon dioxide is also formed.
- 25 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Chemical Equations
Words to symbols
Use symbols and formulae to write a chemical equation for
each of the following reactions.
(a) carbon monoxide + oxygen
carbon dioxide
(b) sulfur + oxygen
sulfur dioxide
(c) carbon + oxygen
carbon monoxide
- 26 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Lesson 11
Conservation of Mass
I can show by experiment the conservation of mass
What happens to the mass of materials when chemical changes take
place?
When a firework sparkler is lit a chemical changes take place: –light and
heat are given off. The magnesium atoms present in the sparkler are
reacting with the oxygen molecules in a combustion reaction to form
magnesium oxide.
Teacher Demo – Magnesium/Oxygen
Aim: To measure mass before and after experiment and see
whether it changes
Method: Your teacher will weigh out approx 0.2g of
magnesium ribbon in a crucible
Results: Record the mass at the start and end in the table below.
Start
End (magnesium oxide)
(magnesium)
Mass
Answer the following questions:
1. Write a word and chemical equation for the reaction taking place:
Word equation:
Chemical equation:
2. In your equation, what do you notice about the number of magnesium
and oxygen atoms on the LHS1 (reactants) and RHS (products) of the
equation?
1
LHS = left hand side, RHS = right hand side
- 27 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
3. Look up the relative atomic mass on p7 of Data Booklet. Calculate the
total mass on the LHS (reactants) and total mass on the RHS
(products). What do you notice?
4. From your results, calculate how much oxygen was used:
Mass of magnesium oxide - magnesium oxide=mass of oxygen used
5. Using your results, calculate the total mass of reactants (magnesium +
oxygen), and mass of product (magnesium oxide). What do you notice?
Does this result agree with your answer to Q3.
- 28 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Learning Outcomes - Chemical Changes & Structure
Tick
Lesson
Learning Outcome
√
No.
1
2
2
3
I can state some signs of a chemical reaction
I can name 3 things which can speed up a chemical
reaction
I can draw and interpret graphs to compare
reaction rates
I can name the 3 subatomic particles, explain
where they are found in an atom and state their
charge
3
I can explain why atoms are electrically neutral
4
I can explain what an atomic number and a mass
number are in an atom
4
I can state the mass of subatomic particles
5
5
6
6
7
7
I can state and draw the electron arrangements
for the first 20 elements
I can state that elements with same number of
outer electrons are grouped together.
I can state that compounds are held together by
bonds
I can state that there are two different types of
bonding (ionic and covalent) when elements join
together, which affect the properties of their
compounds
I can show covalent bonding as a sharing of
electrons by drawing non-metal atoms joined in a
molecule
I can work out the chemical formula given the
number of atoms of each element in a molecule
- 29 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Learning Outcomes - Chemical Changes & Structure
Tick
Lesson
Learning Outcome
√
No.
8
9
9
9
I can explain that an ionic bond is caused by
electrostatic attraction between ions (charged
particles)
I can state the chemical formulae of two element
compounds
I can explain what the endings –ide, -ite and –ate
mean
Extension: I can work out chemical formulae using
valencies (SVSS)
10
I can write a word equation for a chemical reaction
10
I can write simple symbol equations from word
equations
11
I can show by experiment the conservation of mass
- 30 -
CFE Chemistry
Lesson 11
Unit 1 Chemical Changes & Structure
Acids & Alkalis in household substances
I can predict and name some household substances which are
acids and alkalis
You may have previously met the pH scale. Complete the sentences below
for revision.
The pH scale is a range of numbers from __to __.
All acids have a pH of ____than 7.
All alkalis have a pH_____than 7.
Solutions with a pH = 7, are called _______ substances.
Many natural foods are acidic including oranges and they have a sharp
taste. Many cleaning products are alkaline. Can you make a prediction of
the pH of household substances?
Pupil Experiment - pH testing of household substances
Method: Follow the instructions given by your teacher
Results: Complete the table below
Name of food /
drink
Predicted pH
- 31 -
Actual pH
Acid, alkali
or neutral
CFE Chemistry
Unit 1 Chemical Changes & Structure
Can you name some everyday acids and alkalis used in food & drink or
other household substances?
1. What is the pH of an acidic solution and can you name two acidic
solutions that you found?
2. Vinegar contains ethanoic acid, CH3COOH, Lemonade contains
carbonic acid, H2CO3. Circle the correct answers below.
Acids contain metal / non-metal elements.
3.
Which food or drink tested was the most alkaline, explain your
answer?
- 32 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Lesson 12
Making Acids
I can state that non-metal oxides dissolve in water to produce
acids
I can state that an acid solution contains hydrogen ions
How are acids made in the laboratory and in nature?
Your teacher will now demonstrate how acids are made. Complete the
word equations for the two reactions.
Teacher Demo - Making acids
carbon +
carbon
__________
dioxide +
__________
sulfur
+
dioxide +
carbon

dioxide
 ___________ _____
(This acid is used in fizzy drinks!)
oxygen


This acid is one of the main causes of acid rain.
Complete the following table of laboratory acids and answer
the questions that follow:
Name of acid
Formula of Acid
nitric acid
HNO3
sulfuric acid
H2SO4
carbonic acid
H2CO3
hydrochloric acid
HCl
ethanoic acid
CH3COOH
sulfurous acid
H2SO3
- 33 -
Elements present
CFE Chemistry
Unit 1 Chemical Changes & Structure
1. Which type of element is present in all acids?
2. Can you name the element that is found in all acids?
3. The element found in Q2 is present as a charged particle, can you
remember what we call this type of particle found in all acids?
4. Complete the following:
Acids are produced in 2 steps:
1. By burning
in
2. Dissolving the non-metal oxide product in
- 34 -
.
CFE Chemistry
Lesson 13
Unit 1 Chemical Changes & Structure
Making Alkalis
I can state that metal oxides which dissolve in water are called
alkalis
I can state that an alkaline solution contains hydroxide ions
How are alkalis made in the laboratory and in nature?
Previously you learned that all acids contain non-metal elements, but what
about alkalis?
Pupil Experiment - Making alkalis
Aim: To make an alkali from magnesium metal.
Method: Carefully carry out the instructions given to you by
your teacher.
Results & Conclusion: Record your observations from your experiment in
your jotter and your overall findings.
Complete the word equation for this reaction
Magnesium +
__________
Magnesium oxide +
Using information from the table complete the questions that follow:
Name of alkali
Sodium Hydroxide
Formula of Alkali
NaOH
Potassium hydroxide
KOH
Calcium hydroxide
Ca(OH)2
Lithium hydroxide
LiOH
- 35 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
1.
Which types of elements are present in all alkalis?
2.
Which groups in the periodic table do the alkalis come from?
3.
All alkalis contain a charged particle or
the formula
and is called the
, this particle has
ion.
4. Complete the following:
Alkalis are produced in 2 steps:
1. By burning
in
2. Dissolving the metal oxide product in
- 36 -
.
CFE Chemistry
Lesson 14
Unit 1 Chemical Changes & Structure
Acid Rain
I can name acid rain, as an environmental impact caused by
soluble non-metal oxides such as sulfur dioxide
One of the main pollution issues facing the planet is acid rain. Rainwater
with a lower pH than normal (typical water pH 6.5 to 8.5) is called acid
rain.
Investigating acid rain
Using ICT and other resources, answer the following questions
on acid rain:
1.
Can you name the two main non-metal oxide gases that are
responsible for acid rain?
2. What is the main cause for the production of these gases?
3. What effect does acid rain have on rocks and buildings?
- 37 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
4. Why is acid rain a problem for lakes, rivers and streams?
5. Explain some ways in which soils and crops can be affected by acid
rain.
How do soluble oxides impact our local environment?
By studying the water and plant samples in our local area, we can identify
whether pollution, including acid rain has affected our environment.
Pupil Experiment - pH Testing of local water sources
Aim: To identify whether the pH of local water sources may
have been affected by acid rain.
Method:
Use the experiment card provided to carry out your
experiment.
Results: Record your pH values in a results table in your jotter.
Conclusion:
Typical pH values for drinking water are pH 6.5 to 8.5
(Remember pH 7 is a neutral substance). A pH of less than this value,
can indicate possible acid rain contamination. Did you identify whether
the pH of water could have been affected by acid rain?
- 38 -
CFE Chemistry
Lesson 15
Unit 1 Chemical Changes & Structure
Neutralisation
I can state that the reactions of acids with alkalis is a
neutralisation reaction and I can name the products formed
What happens when an acid is added to an alkali?
Acids can be neutralised when they react with substances that raise the
pH of the acid towards 7. Alkalis can also be neutralised when their pH
moves towards 7.
Pupil Experiment - Neutralisation with alkali
Aim: To carry out a neutralisation reaction
Results and Conclusion:
1.
How do you know when the acid was neutralised?
____________________________________________
2.
How did the pH of the acid change as it was neutralised?
____________________________________________
Indigestion tablets are an example of neutralization in day-to-day life.
1.
Why do you have acid in your stomach?
____________________________________________
2. Why might you crush an indigestion tablet before swallowing it?
____________________________________________
- 39 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
What is made in the reaction between an acid and an alkali?
In previous activities you found that acids always contain ________ ions
and that alkalis always contain ________ ions. During neutralisation
these ions react together to form the neutral substance ________. The
other product is formed from the other ions in the acid and the alkali.
Acid +
alkali
HCl
+
water
NaOH
H2O
+
substance X
+
__________
The other product in a neutralisation reaction is called a salt.
Equation practice
Complete the word equations below.
nitric acid +
 sodium nitrate + water
sulfuric acid + potassium hydroxide
 _________ _______+ water
_________acid + ammonium hydroxide  ammonium chloride + water
sulfuric acid + calcium hydroxide  __________ ________ + water
Notice that hydrochloric acid makes ________ salts, sulfuric acid makes
________ salts and nitric acid makes _______ salts.
- 40 -
CFE Chemistry
Lesson 16
Unit 1 Chemical Changes & Structure
Everyday Neutralisation
I can name everyday examples of neutralisation reactions
I can carry out neutralisation experiments and select chemicals
needed to make my own fertiliser
Can you name everyday examples of neutralisation?
1
2
3
Describe the everyday example of neutralisation in each of
the pictures above.
1.
____________________________________________
____________________________________________
2.
____________________________________________
____________________________________________
3.
____________________________________________
____________________________________________
- 41 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Pupil Experiment - Making a fertilizer
Aim: To prepare a sample of potassium nitrate for use as a
fertiliser
Method: Select your chemicals for your salt then
follow instructions in experiment card to make your
own fertiliser.
Results & Conclusion: Write up your experiment
including method, results and conclusion.
Write the word equation for the neutralisation reaction taking place
when making your own fertiliser.
- 42 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Lesson 17 Acid / Carbonate Neutralisation
I can name the products formed from reactions between metal
carbonate and an acid
I can state the test for carbon dioxide gas
I can explain the effect of acid rain on buildings containing
carbonate rocks
What happens when a metal carbonate is added to an acid?
In everyday life metal carbonates are used as indigestion tablets to
neutralise acid.
Method:
Pupil Experiment - Metal Carbonate neutralisation
Aim: In this experiment we will use calcium carbonate (or
marble chips), which is a commonly used building material (e.g.
limestone, marble), to react with hydrochloric acid.
Results: Record all observations and results from your experiment in
your jotter.
Use the questions below to help write a conclusion for this experiment
1.
What happened to the universal indicator in this experiment and
what does this indicate about the gas being produced?
- 43 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
2.
Limewater is used to test for carbon dioxide – if the lime water
turns cloudy - this is a positive test for carbon dioxide. What does
your result indicate?
3.
Can you describe what has happened to the marble chips?
What is made in the reaction between an acid and a metal
carbonate?
Metal carbonate (marble chips) react with acid to produce carbon dioxide
gas & water in a neutralisation reaction. Can you name the other
substance formed from your knowledge of acids and alkalis?
metal carbonate + acid
+ water + Carbon dioxide
Calcium carbonate + Hydrochloric acid

+ carbon dioxide
+ water
Equation practice
Complete the word equations below.
nitric acid + copper carbonate  ________ _________ + water + carbon dioxide
sulfuric acid + sodium carbonate  _________ ________ + water + carbon dioxide
acid +
carbonate  magnesium Chloride+ water + CO2
When acid rain (sulfuric acid) falls on buildings made from calcium
carbonate, a chemical reaction takes place, but what are the products?
- 44 -
CFE Chemistry
Lesson 18
Unit 1 Chemical Changes & Structure
Metal Carbonate Investigation
I can carry out an investigation into metal carbonate/acid
neutralisation reactions
Is the speed of a metal carbonate neutralization reaction
different for different acids?
You know that a metal carbonate will react with an acid to produce a
,
, and
gas.
In this investigation you will use different acids to see if they can affect
the speed of a reaction.
Begin planning your investigation.
Remember to make it a fair
experiment.
Write a conclusion for your results.
This investigation will form part of your assessment for this unit.
- 45 -
CFE Chemistry
Lesson 19
Unit 1 Chemical Changes & Structure
Acid/ Metal Oxide Neutralisation
I can name the products formed when a metal oxide reacts with
an acid
Metal oxides that dissolve in water make
.
What happens
when insoluble metal oxides are added to acids?
Pupil Experiment – Acid/metal oxide neutralisation
Aim:To find out the products formed when a metal oxide
reacts with an acid
Method:
Results & Conclusions: Record your results and conclusion in your
jotter, then answer the following questions:
1. How did you know the acid was neutralised?
____________________________________________
2. Complete the word equation for the reaction:
____________________________________________
3. What type of substance is made, in addition to water?
____________________________________________
4. What is the solid that is left at the bottom of the beaker?
____________________________________________
5. How could this excess solid be removed?
____________________________________________
- 46 -
CFE Chemistry
Lesson 20.
Unit 1 Chemical Changes & Structure
Unusual Everyday Neutralisations
I can state the energy changes in a chemical reaction as
exothermic and endothermic
I can name a practical use of an endothermic reaction
Pupil Experiment: Unusual everyday neutralisation
experiments
Aim: Are all neutralization reactions exothermic (give out heat)?
Method:
Mix the chemicals according to the table below.
Use a
thermometer to measure temperature before and after each chemical is
added to find out if there is an increase or decrease in temperature.
Results: Record your results in a table:
Chemicals
Temperature
start (oC)
Dilute
hydrochloric
acid HCl =
3
(2cm )
+
dilute
sodium NaOH =
3
hydroxide (2cm )
Average =
Solid ammonium carbonate
(small spatula) + ethanoic acid
(2cm3)
Sodium carbonate crystals
(small spatula) + citric acid
powder (small spatula)
In most reactions, the temperature
these reactions are
Temperature
end (oC)
Temp increase or
decrease?
This shows us that
as heat is given out.
A decrease in temperature shows that heat is taken in from the
surroundings and is known as an
reaction.
Ice Packs
Can you explain what happens when an ice pack is used, and how they
work?
- 47 -
CFE Chemistry
Unit 1 Chemical Changes & Structure
Learning Outcomes – Acids & Alkalis
Lesson Learning Outcome
I can predict and name some foods which are acids
11
and alkalis
I can state that non-metal oxides dissolve in water
12
to produce acid solutions
I can state that an acid solution contains hydrogen
12
ions
I can state that metal oxides which dissolve in
13
water are called alkalis
I can state that an alkaline solution contains
13
hydroxide ions
I can name acid rain as an environmental impact
14
caused by soluble non-metal oxides such as sulfur
dioxide
I can state that the reactions of acids with alkalis
15
is a neutralisation reaction and I can name the
products formed
I can name everyday examples of neutralisation
16
reactions
I can carry out neutralisation experiments and
16
select chemicals to make my own fertiliser
I can name the products formed from reactions
17
between a metal carbonate and an acid
17
17
18
19
20
20
I can state the tests for carbon dioxide
I can explain the effect of acid rain on buildings
containing carbonate rocks
I can carry out an investigation into metal
carbonate / acid neutralisation reactions
I can name the products formed when a metal
oxide reacts with an acid
I can state the energy changes in a chemical
reaction as exothermic and endothermic
I can name a practical use of an endothermic
reaction
- 48 -
Tick 