1
Aluminium sulfate, Al2(SO4)3, is used to help relieve the pain caused by bites and stings.
Look at the equation. It shows how aluminium sulfate can be made.
(i) Show that the relative formula mass, Mr, of aluminium sulfate is 342.
The relative atomic mass, Ar, of Al = 27, O = 16 and S = 32.
[1]
(ii) Look at the table of relative formula masses, Mr.
Formula
Mr
Al(OH)3
78
H2SO4
98
Al2(SO4)3
342
H2O
18
Use the information in the table, and the balanced symbol equation, to show that mass is conserved when
aluminium sulfate is made.
[1]
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2
Iron and steel are typical metals.
Iron and steel are good conductors of heat, have a high density and are hard.
Iron and steel are used to make cutting tools called saws.
Describe four other physical properties of metals.
Explain why iron and steel are suitable to make cutting tools such as saws.
The quality of written communication will be assessed in your answer to this question.
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[6]
3
Both diamond and graphite have giant molecular structures.
Silicon dioxide also has a giant molecular structure.
Look at the structure of silicon dioxide.
Explain, using ideas about structure and bonding, why silicon dioxide has a high melting point.
[2]
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4
Hydrogen peroxide solution breaks down to make water and oxygen.
hydrogen peroxide → water + oxygen
The molecular formula for hydrogen peroxide is H2O2.
Calculate the relative formula mass, Mr, of hydrogen peroxide.
The relative atomic mass of H = 1 and of O = 16
relative formula mass =
5
[1]
Look at the diagram.
It shows how the reaction between hydrochloric acid and marble chips (calcium carbonate) can be monitored.
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The reading on the balance decreases during the reaction.
Which of these statements is the best explanation?
A Acid escapes from the flask.
B A gas called hydrogen is made which leaves the flask.
C A gas called carbon dioxide is made which leaves the flask.
D The temperature in the laboratory changes.
Your answer
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[1]
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6
Look at the diagram.
It shows a structure of carbon.
Which structure of carbon is shown in the diagram?
A diamond
B fullerene
C graphene
D graphite
Your answer
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[1]
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7
Hex-1-ene is a carbon-based compound with the formula C6H12.
20.0 g of hex-1-ene is burned in oxygen. Carbon dioxide and water are made. Look at the equation for this
reaction.
C6H12 + 9O2 → 6CO2 + 6H2O
(i) Calculate the number of molecules in 20.0 g of hex-1-ene.
Avogadro’s constant = 6.02 × 1023 mol–1
Give your answer to 3 significant figures.
Number of molecules of C6H12 = .............................. [4]
(ii) Hex-1-ene was burned using a spirit burner in the laboratory.
The diagram shows the spirit burner.
Burning 20.0 g of hex-1-ene should produce 62.9 g of carbon dioxide.
The actual mass of carbon dioxide produced in the reaction was 48.4 g.
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[1]
10
Which statement about phosphorus is correct?
Use the Periodic Table to help you answer this question.
A
A phosphorus atom has 15 protons and 16 electrons.
B
The phosphorus-31 isotope has 16 neutrons.
C
Phosphorus is a metal.
D
The symbol for phosphorus is Po.
Your answer
11
[1]
Fluorine is the most reactive element in Group 7 (Group 17).
Why?
A
Fluorine atoms gain an electron more readily than the other Group 7 elements.
B
Fluorine is a gas.
C
Fluorine exists as diatomic molecules.
D
Fluorine atoms lose electrons more readily than the other Group 7 elements.
Your answer
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[1]
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12
Sodium, Na, reacts with oxygen, O2, to make sodium oxide.
Sodium oxide contains the ions, Na+ and O2?.
The electronic structure for sodium is 2.8.1.
The electronic structure for oxygen is 2.6.
Use ‘dot and cross’ models to describe the bonding in both sodium oxide and in a molecule of oxygen, O2.
You only need to draw the outer shell electrons.
The quality of written communication will be assessed in your answer to this question.
[6]
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13
Which statement best describes an atom?
A
The nucleus is small compared to the atom and contains little of the atom’s mass.
B
The nucleus is large compared to the atom and contains little of the atom’s mass.
C
The nucleus is small compared to the atom and contains most of the atom’s mass.
D
The nucleus is large compared to the atom and contains most of the atom’s mass.
Your answer
[1]
14
This question is about atomic structure.
(i) What is meant by relative atomic mass?
[1]
(ii) What two things can you work out from the atomic number of an element?
1
2
[2]
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15
The mass number of an element is 23.
The atomic number of the same element is 11.
(i) How many protons and how many neutrons are there in an atom of this element?
Number of protons: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Number of neutrons: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
[2]
(ii) This element forms an ion with a charge of +1.
Work out the number of electrons in an ion of this element.
Number of electrons: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
[1]
END OF QUESTION PAPER
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Mark Scheme
Question
1
i
Answer/Indicative content
Marks
[2 × 27] + [3 × 32 ] + [12 × 16] (= 342) (1)
1
Guidance
answer is for the working out not the
answer
allow correct working out e.g. 54 + 96 +192
(= 342)
allow [2 × 27] + [3 × 96] (= 342)
allow 54 + 288 (= 342)
allow 272 (32 + 164)3
Examiner's Comments
Candidates that set out the calculations
carefully were able to show that the relative
formula mass of aluminium sulphate is
342.
ii
any one from:
1
[2 × 78] + [3 × 98] = 342 + [6 × 18] (1)
allow correct numbers to show that mass
of the reactants equals mass of the
products
156 + 294 = 342 + 108 (1)
Examiner's Comments
450 = 450 (1)
Candidates were able to use the
information in the table and the balanced
equation to show that mass is conserved.
Candidate's answers were well structured
and clearly showed the steps involved in
the calculation.
Total
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2
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Mark Scheme
Question
2
Answer/Indicative content
Marks
Level 3
Describes four physical properties of
metals
AND
explains why iron or steel can be used to
make saws
Quality of written communication does not
impede communication of the science at
this level.
Guidance
This question is targeted at grades up to C.
Indicative scientific points may include:
Physical properties of metals
good conductor of electricity
high boiling point
high melting point (ignore heat
resistant)
high tensile strength / strong
malleable (ignore bendy / flexible)
lustrous / shiny
ductile / can be drawn into wires
sonorous
(5–6 marks)
Level 2
Describes four physical properties of
metals
OR
describes two physical properties of metals
and attempts to explain why iron and steel
are used to make saws
Quality of written communication partly
impedes communication of the science at
this level.
ignore good conductor of heat / high
density / hard (stem of question)
ignore easy to shape or bend / durable /
magnetic as properties
(3–4 marks)
Level 1
Describes two physical properties of
metals
OR
attempts to explain why iron and steel are
used to make saws
Quality of written communication impedes
communication of the science at this level.
Explanation linked to use of iron or steel as
a saw
iron or steel is hard
iron or steel can be sharpened
iron is strong (so the saw won't break)
ignore iron or steel is flexible
(1–2 marks)
Level 0
Insufficient or irrelevant science. Answer
not worthy of credit.
Use the L1, L2, L3 annotations in RM
Assessor; do not use ticks.
(0 marks)
Total
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6
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Mark Scheme
Question
3
Answer/Indicative content
Marks
strong covalent bonds (1)
2
Guidance
strong bonds not sufficient
covalent on its own not sufficient
allow covalent bonds are strong
not giant ionic or giant metallic
not intermolecular forces
allow lots of heat needed to break the
bonds
ignore harder to break bonds
ignore more heat needed to break bonds
ignore high temperature
not lots of energy needed to break ionic or
metallic bonds
lots of energy needed to break the bonds
(1)
Examiner's Comments
This answer required candidates to write
about strong covalent bonds and lots of
energy needed to break these strong
covalent bonds. Many candidates wrote
about bonds but were not specific about
them being strong covalent bonds. They
also wrote about needing more energy to
break them but not about the need for lots
of energy.
4
5
6
Total
2
34 (1)
1
Total
1
C
1
Total
1
D
1
Total
1
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Mark Scheme
Question
7
i
Answer/Indicative content
FIRST CHECK THE ANSWER ON
ANSWER LINE
If answer = 1.44 × 1023 award 4 marks
Atomic weight = (6×12) + (1×12)
= 84g ✓
Marks
Guidance
4
ALLOW correct answer to 3 sig figs from
moles of hex-1-ene (0.24 / 0.238 / 0.2381)
[0.238 gives 1.43 × 1023; 0.2381 gives 1.43
× 1023)
(AO3 ×
2.2)
Moles of hex-1-exe = 20 ÷ 84
= 0.24 / 0.238 / 0.2381 ✓
ALLOW ECF from incorrect atomic weight
Number of molecules = 0.24 × (6.02×1023)
= 1.4448 × 1023 ✓
ALLOW ECF from incorrect number of
moles
= 1.44 × 1023 (3sf) ✓
(AO1.2)
ECF if processing of data has given an
incorrect value but expressed as 3SF
Examiner’s Comments
The calculation of atomic weight of
Hex-1-ene was the section of the
calculation where candidates gained the
most credit. Fewer candidates could
correctly calculate the number of moles of
Hex-1-ene. The most common
misconception here was the numbers
being placed in the wrong place in the
calculation. Even fewer candidates could
then multiply by Avogadro’s Constant to
give the number of molecules. Standard
form could only be handled correctly by the
higher ability candidates. A significant
number of candidates gained in mark by
the conversion of a calculated value to
three significant figures.
Exemplar 7
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Mark Scheme
Question
Answer/Indicative content
Marks
Guidance
This exemplar shows the expected steps of
the calculation and was given 4 marks as it
has the final answer to the correct number
of significant figures.
Exemplar 8
This exemplar shows all but the step where
there should be a multiplication of
Avogadro’s Constant. This was given 3
marks for just one error in missing a stage
of the calculation.
ii
Not enough oxygen / oxygen was a limiting
reactant ✓
1
(AO3.2b)
ALLOW idea that incomplete combustion
occurred
Examiner’s Comments
A large number of candidates discussed
the amount of oxygen present and tried to
calculate its numerical value rather than
simply stating that the mass of oxygen
would be less or limited.
Total
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Mark Scheme
Question
8
Answer/Indicative content
A✓
Marks
1 (AO2.1)
Guidance
ALLOW 9
Examiner’s Comments
Most candidates correctly selected A, but a
few thought that the relative atomic mass
indicated the number of protons so chose
C.
9
Total
1
C✓
1 (AO
2.2)
Examiner’s Comments
Only higher ability candidates correctly
identified 2.0 grams as the correct
response. Those who did gain credit here
often used the space at the side of the
question for calculations.
10
Total
1
B✓
1 (AO
2.1)
Examiner’s Comments
Approximately half of the candidates could
use the periodic table as directed in the
question to identify the isotope of
phosphorous 31 as having 16 neutrons.
The most commonly seen incorrect
response was the imbalance of protons
and electrons for an isotope, showing a
misconception in the understanding of
atomic mass and atomic number.
11
Total
1
A✓
1 (AO
1.1)
Total
1
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Examiner’s Comments
Most candidates answered this correctly.
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Mark Scheme
Question
12
Answer/Indicative content
Marks
[Level 3]
Use the dot and cross model to explain the
covalent bonding in an oxygen molecule
AND
draw the electronic structures of the
sodium ion and the oxide ion
Quality of written communication does not
impede communication of the science at
this level
6
(5 – 6 marks)
[Level 2]
Use the dot and cross model to explain the
covalent bonding in an oxygen molecule
OR
Uses the dot and cross model to draw the
electronic structures of the sodium ion and
the oxide ion
Quality of written communication partly
impedes communication of the science at
this level
(3 – 4 marks)
[Level 1]
States or shows that O2 is bonded
covalently
OR
Na2O by ionic bonding
Quality of written communication impedes
communication of the science at this level
(1 – 2 marks)
[Level 0]
Insufficient or irrelevant science. Answer
not worthy of credit.
Guidance
This question is targeted at grades up to
A*.
Indicative scientific points at all levels 2
and 3 could include:
Dot and cross diagram for oxygen
Electronic structure of sodium ion (no
need to have charge but if shown must
be correct)
Electronic structure of oxide ion (no
need to have charge but if shown must
be correct)
Idea that positive sodium ion attracts a
negative oxide ion
allow Na+ or an empty shell for electronic
structure of sodium ion
ignore inner shells if drawn
Indicative scientific points at level 1 could
include:
O2 has covalent bonding
O2 has shared pairs of electrons
Na2O has ionic bonding
Na2O bonding involves electron
transfer
Na loses electron and O gains
electrons
Use the L1, L2, L3 annotations in scoris.
Do not use ticks.
See next page for dot and cross diagrams.
(0 marks)
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Mark Scheme
Question
Answer/Indicative content
Marks
Guidance
At level 2 and 3, if dot and cross diagram
shows the same electron on the sodium
ion and the oxide ion then answer is limited
to lower mark within level
Credit word descriptions however for level
2 or 3 correct electron structures must be
described eg Na+ 2.8 O2? 2.8
Examiner's Comments
In many answers ideas about covalent and
ionic bonding were mixed up. Some
candidates did not realise that two models
were required, and instead attempted to
integrate the two. The few candidates that
attempted the structure of O2 scored well.
13
Total
6
C✓
1
(AO1.1)
Total
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Examiner’s Comments
Almost half of candidates correctly
selected C. A common misconception is
that the nucleus is large compared to the
size of the atom with B and D being
common choices.
1
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Mark Scheme
Question
14
i
ii
Answer/Indicative content
Marks
Guidance
The mean mass of an atom compared to
1/12th of the mass of an atom of Carbon-12
✓
1
(AO1.1)
ALLOW The mean or average mass of an
atom compared to Carbon-12
(Number of) protons ✓
(Number of) electrons ✓
2
(AO2 ×
1.1)
Examiner’s Comments
Most candidates confused this with mass
number and referred to the number of
protons and neutrons. Almost no
candidates managed to explain correctly or
even mentioned carbon 12. Many thought
it was the mass of one atom.
ALLOW position in the Periodic Table
because you can identify the element
ALLOW number of electrons in the outer
shell
ALLOW number of (electron) shells /
period number
Examiner’s Comments
This question differentiated well with higher
ability candidates scoring 2 marks for
number of protons and number of
electrons. Most candidates scored at least
one mark for stating the number of protons.
However, many candidates confused
atomic number and mass number and
referred to the number of neutrons. A few
candidates put more than 2 answers which
resulted in a loss of credit e.g. 1. Number
of protons and neutrons (no mark) 2.
Number of electrons (1 mark). Some just
wrote ‘protons’ rather than ‘number of
protons’, but were credited with the mark.
Some candidates interpreted the question
differently and stated things they could
deduce e.g. the number of electrons in the
outer shell, number of electron shells,
period number. They did gain credit for
this, although it was not what the question
had intended.
Total
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Mark Scheme
Question
15
Answer/Indicative content
i
Protons = 11 (1)
Neutrons = 12 (1)
2
ii
10
1
Total
3
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Marks
22 of 22
Guidance
ECF number of electrons/protons minus 1
(1 )
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