HIGHER CHEMISTRY
PAST PAPERS 2000 - 2010
Lesmahagow High School
Higher Chemistry
Trends and Bonding - Past Paper Homework
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HIGHER CHEMISTRY
PAST PAPERS 2000 - 2010
Trends in the Periodic Table
1.
2000
Ionisation energies provide information about the structure of atoms.
(a)
Write the equation, showing state symbols, for the first ionisation energy of sodium.
(b)
Calculate the number of electrons lost when one mole of boron atoms is converted into
one mole of boron ions with a charge of 3+.
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1
(2)
2001
2.
On crossing the Periodic Table, there are trends in the sizes of atoms and ions.
(a)
Why is the atomic size of chlorine less than that of sodium?
1
(b)
Ion
Si4+
P3-
Ionic radius/pm
42
198
Why is there a large increase in ionic radius on going from Si4+ to P3-?
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(2)
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HIGHER CHEMISTRY
3.
4.
PAST PAPERS 2000 - 2010
2002
The three statements below are taken from a note made by a student who is studying trends in
the Periodic Table.
(a)
Complete the note above to give the heading for the third statement
(b)
What is the trend in the first ionisation energy across a period from left to right?
(c)
Why is the second ionisation energy of sodium so much greater than its first ionisation
energy?
(a)
(b)
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1
1
(3)
2004
Aluminium and phosphorus are close to one another in the Periodic Table but the P3- ion
is much larger than the Al3+ ion.
Give a reason for this difference.
The P3- ion and the Ca2+ ion have the same electron arrangement but the Ca2+ ion is
smaller than the P3- ion.
Give the reason for this difference.
3
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1
(2)
HIGHER CHEMISTRY
5.
PAST PAPERS 2000 - 2010
2006
The elements in the second row of the Periodic Table are shown below.
(a)
Why does the atomic size decrease crossing the period from lithium to neon?
(b)
Diamond and graphite are forms of carbon that exist as network solids.
Name a form of carbon that exists as discrete molecules.
(c)
Use the electronegativity values to explain why nitrogen chloride contains pure covalent
bonds.
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1
1
(3)
2007
6.
(a)
Atoms of different elements have different attractions for bonded electrons.
What term is used as a measure of the attraction an atom involved in a bond has for the
electrons of the bond?
(b)
Atoms of different elements are different sizes.
What is the trend in atomic size across the period from sodium to argon?
(c)
Atoms of different elements have different ionisation energies.
Explain clearly why the first ionisation energy of potassium is less than the first ionisation
energy of sodium.
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1
1
2
(4)
HIGHER CHEMISTRY
7.
(a)
PAST PAPERS 2000 - 2010
2009
Lithium starts the second period of the Periodic Table.
What is the trend in electronegativity values across this period from Li to F?
(b)
Graph 1 shows the first four ionisation energies for aluminium.
Why is the fourth ionisation energy of aluminium so much higher than the third ionisation
energy?
(c)
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1
Graph 2 shows the boiling points of the elements in Group 7 of the Periodic Table.
Why do the boiling points increase down Group 7?
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1
(3)
HIGHER CHEMISTRY
8.
PAST PAPERS 2000 - 2010
2009
The following answers were taken from a student’s examination paper.
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(1)
2010
9.
(a)
The first ionisation energy of an element is defined as the energy required to remove one
mole of electrons from one mole of atoms in the gaseous state.
The graph shows the first ionisation energies of the Group 1 elements.
2
(b)
(i)
Clearly explain why the first ionisation energy decreases down this group.
(ii)
The energy needed to remove one electron from one helium atom is
3.94 x 10-211 kJ.
Calculate the first ionisation energy of helium, in kJ mol-1.
1
The ability of an atom to form a negative ion is measured by its Electron Affinity.
The Electron Affinity is defined as the energy change when one mole of gaseous atoms of an
element combines with one mole of electrons to form gaseous negative ions.
Write the equation, showing state symbols, that represents the Electron Affinity of chlorine
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(4)
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HIGHER CHEMISTRY
PAST PAPERS 2000 - 2010
Bonding, Structure and Properties
2000
1.
Diphosphine, P2H4, is a hydride of phosphorus. All of the covalent bonds in diphosphine
molecules are non-polar because the elements present have the same electronegativity.
(a)
What is meant by the term ‘electronegativity’?
(b)
The balanced equation for the complete combustion of diphosphine is:
2P2H4(g) + 7O2(g)
P4O10(s) + 4H2O(l)
What volume of oxygen would be required for the complete combustion of 10cm3 of
diphosphine?
(c)
2.
1
Calculate the volume occupied by 0.330g of diphosphine.
(Take the molar volume to be 24.0 litres mol-1.)
(Show your working clearly)
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1
(3)
2000
In 1996, the scientists Robert Curl, Harold Kroto and Richard Smalley won the Nobel Prize in
Chemistry for their contribution to the discovery of new forms of carbon called fullerenes.
(a)
In what way does the structure of fullerenes differ from the other forms of carbon,
diamond and graphite?
(b)
One form of fullerene, C60, forms a superconducting crystalline compound with potassium.
Its formula can be represented as K3C60.
A sample of this compound was found to contain 2.88g of carbon.
(i)
Calculate the number of moles of fullerene used to make this compound.
(ii)
Calculate the mass of potassium, in grams, in the sample.
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1
(3)
HIGHER CHEMISTRY
PAST PAPERS 2000 - 2010
2002
3.
A mass spectrometer is an instrument that can be used to gain information about the masses of
molecules.
When hydrogen fluoride is analysed in a mass spectrometer, as well as molecules with a relative
molecular mass of 20, some ‘double molecules’ (relative molecular mass 40) and ‘triple molecules’
(relative molecular mass 60) are found to exist. No such molecules are found when the elements,
hydrogen and fluorine, are separately analysed.
(a)
(b)
Name the weak force of attraction between molecules that is found in both liquid hydrogen
and liquid fluorine.
Why are ‘double’ and ‘triple’ molecules found in hydrogen fluoride but not in hydrogen and
not in fluorine?
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1
(2)
2003
4.
Although propane and ethanol have similar molecular masses, the alkane is a gas at room
temperature while the alcohol is a liquid. This difference in boiling points is due to the different
strengths of the intermolecular forces in the two compounds.
Explain why propane is a gas at room temperature while ethanol is a liquid.
In your answer you should name the intermolecular forces involved in each compound and explain
how they arise.
4
2004
5.
(a)
Complete the table below by adding the name of an element from elements 1 to 20 of
the Periodic Table for each of the types of bonding and structure described.
Bonding and Structure at room
temperature and pressure
Name of element
Metallic solid
Sodium
Monatomic gas
Covalent network solid
Discrete covalent molecular gas
2
Discrete covalent molecular solid
(b)
Why do metallic solids such as sodium conduct electricity?
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1
(3)
HIGHER CHEMISTRY
PAST PAPERS 2000 - 2010
2006
6.
The melting and boiling points and electrical conductivities of four substances are given in the
table.
Substance
Melting
point/˚C
Boiling
point/˚C
A
B
C
D
92
1050
773
1883
190
2500
1407
2503
Solid
conducts
electricity?
No
Yes
No
No
Melt
conducts
electricity?
No
Yes
Yes
no
Complete the table below by adding the appropriate letter for each type of bonding and
structure.
Substance
Bonding and structure at
room temperature
Covalent molecular
Covalent network
Ionic
Metallic
(2)
2007
7.
Compared to other gases made up of molecules of similar molecular masses, ammonia has a
relatively high boiling point.
In terms of intermolecular bonding present, explain clearly why ammonia has a relatively high
boiling point
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2
(2)
HIGHER CHEMISTRY
8.
(a)
PAST PAPERS 2000 - 2010
2008
The graph shows how the freezing point changes with changing concentration for aqueous
solutions of sodium chloride and ethane-1,2-diol.
(i) Draw a structural formula for ethane-1,2-diol.
(ii) Ethane-1,2-diol solution is used as an antifreeze in car radiators, yet from the graph
it would appear that sodium chloride solution is more efficient.
Suggest why sodium chloride solution is not used as an antifreeze.
(b)
Boiling points can be used to compare the strengths of the intermolecular forces in alkanes
with the strengths of the intermolecular forces in diols.
Name the alkane that should be used to make a valid comparison between the strength of
its intermolecular forces and those in ethane-1,2-diol.
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1
1
(3)
2008
9.
The formulae for three oxides of sodium, carbon and silicon are Na2O, CO2 and SiO2.
Complete the table for CO2 and SiO2 to show both the bonding and structure of the three
oxides at room temperature.
Oxide
Bonding and Structure
Na2O
Ionic lattice
CO2
SiO2
10.
(2)
2010
The elements lithium, boron and nitrogen are in the second period of the Periodic Table.
Compare the table below to show both the bonding and structure of these three elements at
room temperature.
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(2)
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HIGHER CHEMISTRY
10.
Hydrogen cyanide HCN, is highly toxic.
PAST PAPERS 2000 - 2010
2010
Information about hydrogen cyanide is given in the table.
Although hydrogen cyanide has a similar mass to nitrogen, it has a much higher boiling point.
This is due to the permanent dipole-permanent dipole attractions in liquid hydrogen cyanide.
What is meant by permanent dipole-permanent dipole attractions?
2
(2)
Explain how they arise in hydrogen cyanide.
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