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Q1. Crude oil contains many different hydrocarbons.
(i) Which formula in the list represents a hydrocarbon? Draw a ring around the correct formula.
CO2 C6H12O6 C8H18 H2O
(1)
(ii) Which word from the list below best describes crude oil? Draw a ring around the correct word.
alloy compound element mixture (1)
(iii) Choose, from the list below, words to complete the passage about the separation of the hydrocarbons in crude oil by fractional distillation.
atoms burned condensed evaporated filtered
fractions ions molecules neutralised
During fractional distillation the many hydrocarbons in crude oil are separated
into ................................. each of which contains ................................ with a
similar number of carbon .................................... .
To do this the oil is first .................................... and then ....................................
at a number of different temperatures. (5)
(Total 7 marks)
Q2. The diagram shows a carbon atom.
(a) (i) A proton is labelled.
Use the correct answer from the box to label each of the other sub-atomic particles.
(2)
electron ion molecule neutron
Page 1 of 40
(ii) The atom of carbon is represented as:
What is the mass number of this carbon atom?
Draw a ring around the correct answer.
6 13 19 (1)
(iii) Complete the sentence.
Atoms of carbon have no overall electrical charge because the number
of protons is the same as the number of ............................................. . (1)
(b) Butane is represented as:
(i) Use the correct answer from the box to complete each sentence.
Butane is a ...................................... .
Butane contains atoms of carbon and ...................................... .
Each line between the atoms in butane represents a chemical .................................. .
(3)
bond compound helium hydrogen mixture oxygen
(ii) Which is the correct formula for butane?
Tick (✔) one box.
(1) (Total 8 marks)
C4H
4
C4H
8
C4H
10
Page 2 of 40
Q3. This question is about oil reserves.
(a) Diesel is separated from crude oil by fractional distillation.
Describe the steps involved in the fractional distillation of crude oil.
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(b) Diesel is a mixture of lots of different alkanes.
What are alkanes?
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Page 3 of 40
(c) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.
Petroleum products, such as petrol, are produced from crude oil. The graph shows the possible future production of petroleum products from crude oil and the expected demand for petroleum products.
Canada’s oil sands hold about 20% of the world’s known crude oil reserves.
The oil sands contain between 10 to 15% of crude oil. This crude oil is mainly bitumen.
In Canada the oil sands are found in the ground underneath a very large area of forest. The trees are removed. Then large diggers and trucks remove 30 metres depth of soil and rock to reach the oil sands. The oil sands are quarried. Boiling water is mixed with the quarried oil sands to separate the bitumen from the sand. Methane (natural gas) is burned to heat the water.
The mixture can be separated because bitumen floats on water and the sand sinks to the bottom of the water. The bitumen is cracked and the products are separated by fractional distillation.
Page 4 of 40
Use the information given and your knowledge and understanding to suggest the advantages and disadvantages of extracting petroleum products from oil sands.
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(Total 11 marks)
Page 5 of 40
Q4. Crude oil is a mixture of a very large number of compounds.
Figure 1 shows a laboratory experiment to separate crude oil.
Figure 1
(a) Complete the sentence.
The name for compounds that contain only hydrogen and
carbon is ...................................................................... . (1)
(b) Use the correct word from the box to complete each sentence.
(i) The process of separating crude oil is fractional ........................... . (1)
condensation decomposition distillation evaporation reduction
(ii) The process taking place at A is ............................................... . (1)
(iii) The process taking place at B is .............................................. . (1)
(c) One of the compounds in crude oil is hexane. The displayed structure of hexane is shown in Figure 2.
Figure 2
Complete the sentences.
(i) Each line between the atoms in hexane represents a covalent ............................... . (1)
Page 6 of 40
(ii) Complete the chemical formula for hexane.
C6H............
(1)
(iii) Hexane can be broken down into smaller molecules by a process called
................................ . (1)
(d) Small molecules, called alkenes, are used to make polymers.
(i) Name the polymer made from butene.
............................................................................................................ . (1)
(ii) Incinerators are used to burn waste polymers, such as plastic bags.
Tick (✓) one advantage and tick (✓) one disadvantage of burning plastic bags.
(2) (Total 10 marks)
Advantage
Tick (✓✓✓✓) Disadvantage
Tick (✓✓✓✓)
Energy is released.
More recycling is needed.
Carbon dioxide is produced.
Q5. Crude oil is a fossil fuel.
(a) Describe how crude oil is separated into fractions.
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(b) Fuel oil is one of the fractions from crude oil.
Power stations burn fuel oil to generate electricity. The waste gases from the combustion of fuel oil contain carbon dioxide, water vapour, sulfur dioxide and oxides of nitrogen.
The waste gases are passed through a suspension of limestone in water. Limestone is mainly calcium carbonate.
Suggest how the use of a suspension of limestone decreases one of the environmental impacts that the waste gases would cause.
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........................................................................................................................ (3)
(c) Some fractions from crude oil contain large hydrocarbon molecules.
(i) Hydrocarbon molecules, such as decane, can be cracked to produce smaller, more useful molecules.
Write the correct formula of the third product to complete the chemical equation.
You do not need to give the name of this product.
C10
H22
C5H
10 + C
3H
8 + ........................
decane pentene propane (1)
(ii) Pentene is used to produce poly(pentene).
Complete the equation and the displayed structure of poly(pentene).
(3)
Page 8 of 40
(iii) Some polymers are described as smart polymers.
Suggest one property of a smart polymer that is different to that of an ordinary polymer.
...............................................................................................................
............................................................................................................... (1)
(Total 12 marks)
Q6. The figure below shows the displayed structures of five organic compounds, A, B, C, D and E.
(a) Choose which organic compound, A, B, C, D or E, matches the descriptions.
You may choose each compound once, more than once or not at all.
Write the letter of the compound that:
(i) is a saturated hydrocarbon (1)
A B C
D E
(ii) comes from a homologous series with the general formula CnH2n (1)
(iii) has the empirical formula C2H
6O
(1)
(iv) reacts with calcium carbonate to produce carbon dioxide (1)
(v) reacts with compound A to produce compound C. (1)
Page 9 of 40
(b) Compound B (C2H4) and C8H18 are produced by cracking C14H30
C14
H30
3C2H
4 + C
8H
18
(i) Give two conditions for cracking.
...............................................................................................................
............................................................................................................... (2)
(ii) Explain why C8H18 has a lower boiling point than C14H30
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(c) Compound B is a colourless gas.
Give a chemical test and its result to show that compound B is unsaturated.
Test ...............................................................................................................
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Result ............................................................................................................
........................................................................................................................ (2)
(d) Compound B is ethene.
Complete the equation to show the formation of poly(ethene) from ethene.
(3)
(Total 14 marks)
Page 10 of 40
Q7. Sulfur is a non-metal.
Sulfur burns in the air to produce sulfur dioxide, SO2
(a) Why is it important that sulfur dioxide is not released into the atmosphere?
Tick (✔) one box.
(1)
Sulfur dioxide causes acid rain.
Sulfur dioxide causes global dimming.
Sulfur dioxide causes global warming.
(b) Sulfur dioxide dissolves in water.
What colour is universal indicator in a solution of sulfur dioxide? Give a reason for your answer.
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(c) Sulfur dioxide is a gas at room temperature.
The bonding in sulfur dioxide is covalent.
Explain, in terms of its structure and bonding, why sulfur dioxide has a low boiling point.
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(d) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.
Sulfur dioxide is produced when fossil fuels are burned.
It is important that sulfur dioxide is not released into the atmosphere.
Three of the methods used to remove sulfur dioxide from gases produced when fossil fuels are burned are:
• wet gas desulfurisation (W)
• dry gas desulfurisation (D)
• seawater gas desulfurisation (S).
Information about the three methods is given in the bar chart and in Table 1 and Table 2.
Method of removing sulfur dioxide
Table 1
Method Material used How material is obtained
W Calcium carbonate, CaCO3 Quarrying
D Calcium oxide, CaO Thermal decomposition of calcium
carbonate: CaCO
3 CaO + CO
2
S Seawater From the sea
Table 2
Method What is done with waste material
W Solid waste is sold for use in buildings. Carbon dioxide is released into the atmosphere.
D Solid waste is sent to landfill.
S Liquid waste is returned to the sea.
Page 12 of 40
Evaluate the three methods of removing sulfur dioxide from waste gases.
Compare the three methods and give a justified conclusion.
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(Total 12 marks)
Q8. Crude oil is a fossil fuel.
(a) To make crude oil more useful it is separated into fractions.
Use the correct word from the box to complete each sentence.
boiling compound decomposition distillation
filtration mixture molecule
(i) Crude oil is a .................................................. of different substances. (1)
(ii) The substances in crude oil have different
.................................................. points. (1)
(iii) Crude oil is separated by fractional .................................................. . (1)
Page 13 of 40
(b) Petrol is one of the fractions produced from crude oil.
Car engines use a mixture of petrol and air.
The diagram shows some of the gases produced.
(i) What type of reaction happens to petrol in a car engine?
(1)
Tick ( ) one box.
combustion
decomposition
neutralisation
(ii) Petrol contains octane (C8H18).
Complete the word equation for the reaction of octane with oxygen.
octane + ............................ ............................ + ............................ (2)
(iii) Cars use sulfur-free petrol as a fuel.
Describe why sulfur should be removed from petrol.
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Page 14 of 40
(c) Some fractions from crude oil contain large hydrocarbon molecules.
These molecules can be cracked to produce smaller, more useful molecules.
An equation for cracking decane is:
C10
H22
C3H
8 + C
2H
4 + C
5H
10
decane propane ethene pentene
(i) Why is propane useful?
(1)
Tick ( ) one box.
Propane is a polymer.
Propane is an alloy.
Propane is a fuel.
(ii) Draw bonds to complete the displayed structure of ethene.
(1)
(iii) What is the colour change when bromine water reacts with ethene?
(1)
Tick ( ) one box.
Orange to colourless
Orange to green
Orange to red
Page 15 of 40
(iv) Complete the sentence.
Pentene is useful because many pentene molecules can join together
to form .................................................. . (1)
(Total 12 marks)
Q9. This question is about organic compounds.
Hydrocarbons can be cracked to produce smaller molecules.
The equation shows the reaction for a hydrocarbon, C18H38
C18
H38 → C
6H
14 + C
4H
8 + 2 C
3H
6 + C
2H
4
(a) Which product of the reaction shown is an alkane?
(1)
Tick one box.
C2H
4
C3H
6
C4H
8
C6H
14
Page 16 of 40
(b) The table below shows the boiling point, flammability and viscosity of C18H38 compared
with the other hydrocarbons shown in the equation.
Which letter, A, B, C or D, shows how the properties of C18
H38
compare with the
properties of C2H4, C3H6, C4H8 and C6H14?
(1)
Boiling point Flammability Viscosity
A highest lowest highest
B highest lowest lowest
C lowest highest highest
D lowest highest lowest
Tick one box.
A
B
C
D
Page 17 of 40
(c) The hydrocarbon C4H
8 was burnt in air.
Incomplete combustion occurred.
Which equation, A, B, C or D, correctly represents the incomplete combustion reaction?
A C4H8 + 4O → 4CO + 4H2
B C4H
8 + 4O
2 → 4CO + 4H
2O
C C4H8 + 6O2 → 4CO2 + 4H2O
D C4H
8 + 8O → 4CO
2 + 4H
2
(1)
Tick one box.
A
B
C
D
(d) Propanoic acid is a carboxylic acid.
Which structure, A, B, C or D, shows propanoic acid?
(1)
Tick one box.
A
B
C
D
Page 18 of 40
(e) Propanoic acid is formed by the oxidation of which organic compound?
(1) (Total 5 marks)
Tick one box.
Propane
Propene
Propanol
Polyester
Q10. A student investigated the viscosity of liquid hydrocarbons.
A viscous liquid is a liquid that flows slowly.
The student used this method.
• Measure 50 cm3 of the liquid hydrocarbon.
• Pour the liquid hydrocarbon into the funnel, as shown in Figure 1.
• Time how long it takes for all of the liquid hydrocarbon to run out of the funnel.
• Repeat the experiment for other liquid hydrocarbons.
(a) (i) Give the name of apparatus A in Figure 1.
............................................................................................................... (1)
(ii) Name the apparatus that could be used to measure 50 cm3 of liquid hydrocarbon.
............................................................................................................... (1)
Page 19 of 40
(b) The student’s results for six liquid hydrocarbons are shown in Table 1.
Table 1
Formula of liquid hydrocarbon
Time for liquid hydrocarbon to run out of the funnel in seconds Mean time in
seconds Experiment 1 Experiment 2 Experiment 3
C5H12
12 11 13 12
C6H
14
14 15 15 15
C7H16
19 20 18
C8H
18
27 26 28 27
C10H22
46 48
47
C12H26
65 67 69 67
Page 20 of 40
(i) The student did the experiment three times with each liquid hydrocarbon.
Give two reasons why.
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(ii) Use the data in Table 1 to calculate the mean time, in seconds, for C7H
16
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Mean time = ................................... seconds (1)
(iii) Complete the sentence.
As the number of carbon atoms in a molecule of liquid hydrocarbon increases, the time taken for the liquid hydrocarbon to run out of the funnel ................................................ .
(1)
(iv) A ring has been drawn around one result in Table 1.
This result has not been used to calculate the mean time for C10H22
Suggest why this result was not used.
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(v) Suggest one error the student may have made to get the ringed result.
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Page 21 of 40
(c) The student investigated the effect of temperature on the viscosity of one of the liquid hydrocarbons.
The liquid hydrocarbon he was using had the hazard symbols shown in Figure 2.
(i) Suggest why the student warmed the liquid hydrocarbon using warm water and not a Bunsen flame.
...............................................................................................................
............................................................................................................... (1)
(ii) The student wore safety glasses.
Give one other safety precaution the student should take, and give a reason for this safety precaution.
Safety precaution .................................................................................
Reason .................................................................................................
............................................................................................................... (2)
(d) This is the method the student used to investigate the effect of temperature on the viscosity of one of the liquid hydrocarbons.
• Measure 50 cm3 of the liquid hydrocarbon and pour it into a beaker.
• Stand the beaker of liquid hydrocarbon in a heated water bath.
• Leave for a few minutes.
• Measure the temperature of the liquid hydrocarbon.
• Pour the liquid hydrocarbon into the funnel, as shown in Figure 3.
Page 22 of 40
• Time how long it takes for all of the liquid hydrocarbon to run out of the funnel.
• Repeat the experiment at different temperatures.
(i) The student’s results are shown in Table 2.
Table 2
Temperature of liquid
hydrocarbon in °C Time to run out of the
funnel in seconds
23 27
30 21
37 17
46 16
55 11
65 9
Page 23 of 40
Plot the results shown in Table 2 on the graph in Figure 4.
Draw a curve of best fit.
(3)
(ii) One of the points is anomalous.
Draw a ring around the anomalous point on your graph. (1)
(iii) Predict how long it will take the liquid hydrocarbon to run through the funnel at 70 °C.
Show your working on your graph.
Time = ........................................ seconds (2)
(iv) Describe the relationship between the temperature of the liquid hydrocarbon and the viscosity of the liquid hydrocarbon.
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(v) The apparatus the student used in Figure 2 could lead to a systematic error in the results.
Identify one source of systematic error, and describe how the student could avoid or reduce the error.
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Page 24 of 40
(2) (Total 22 marks)
Q11. Crude oil is a mixture of a large number of compounds most of which are hydrocarbons such as the molecule shown below.
(a) What is a hydrocarbon?
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............................................................................................................................. (1)
(b) What is the chemical formula of the molecule shown above?
............................................................................................................................. (1)
(e) The cracking of large molecules obtained from crude oil is one of the important processes in an oil refinery. Cracking involves the thermal decomposition of large molecules. The diagram below shows an apparatus that can be used to demonstrate cracking in the laboratory. The porous pot acts as a catalyst in the reaction.
(i) What happens during thermal decomposition?
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(ii) What effect does the porous pot catalyst have on the reaction?
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Page 25 of 40
(iii) Complete the equation below for the cracking of the molecule. C20H42.
C20
H42 → C
12H
26 + ............................................
(1) (Total 6 marks)
Q12. This question is about hydrocarbons.
(a) The names and formulae of three hydrocarbons in the same homologous series are:
Ethane C2H6
Propane C3H
8
Butane C4H10
The next member in the series is pentane.
What is the formula of pentane?
........................................................................................................................ (1)
(b) Which homologous series contains ethane, propane and butane?
(1)
Tick one box.
Alcohols
Alkanes
Alkenes
Carboxylic acids
(c) Propane (C3H
8) is used as a fuel.
Complete the equation for the complete combustion of propane.
C3H8 + 5O2 → 3 .............................. + 4 .................................
(2)
(d) Octane (C8H
18) is a hydrocarbon found in petrol.
Explain why octane is a hydrocarbon.
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Page 26 of 40
(e) The table below gives information about the pollutants produced by cars using diesel or petrol as a fuel.
Compare the pollutants from cars using diesel with those from cars using petrol.
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Fuel Relative amounts of pollutants
Oxides of Nitrogen
Particulate matter
Carbon dioxide
Diesel 31 100 85
Petrol 23 0 100
(f) Pollutants cause environmental impacts.
Draw one line from each pollutant to the environmental impact caused by the pollutant.
(2) (Total 11 marks)
Pollutant Environmental impact
caused by the pollutant
Acid rain
Oxides of nitrogen Flooding
Global dimming
Particulate matter Global warming
Photosynthesis
Page 27 of 40
M1. (i) C8H
18
for one mark 1
(ii) mixture for one mark
1
(iii) fractions molecules atoms evaporated condensed
in this order for 1 mark each 5
[7]
M2. (a) (i) Neutron (top label) 1
Electron (bottom label) 1
(ii) 13 1
(iii) electrons 1
(b) (i) compound 1
hydrogen 1
bond 1
(ii) C4H
10
1 [8]
M3. (a) heat to vaporise (the crude oil)
do not accept cracking / burning 1
vapours condense 1
at different temperatures allow they have different boiling points
1
Page 28 of 40
(b) (alkanes) are hydrocarbons or are compounds of hydrogen and carbon only 1
alkanes are saturated or have only (carbon-carbon) single bonds
accept have no (carbon-carbon) double bonds accept general formula is C
nH
2n+2 for 2 marks
1
(c) Marks awarded for this answer will be determined by the Quality of Written Communication (QWC) as well as the standard of the scientific response.
0 marks No relevant content.
Level 1 (1-2 marks) There is a basic description of at least one advantage or one disadvantage of extracting petroleum products from oil sands.
Level 2 (3-4 marks) There is a clear description of an advantage and a disadvantage of extracting petroleum products from oil sands.
Level 3 (5-6 marks) There is a detailed description of both advantages and disadvantages of extracting petroleum products from oil sands.
Page 29 of 40
Examples of the chemistry/environmental/economic/social points made in the response
Advantages:
• the oil sands are needed because crude oil is running out
• this crude oil is needed because demand is increasing
• the oil sands contain a large amount of crude oil
• the oil sands could improve Canada’s economy
• the oil sands provide employment for a lot of people
• the trees / forest are used for wood products / fuel
Disadvantages:
• destruction of environment / habitats
• fewer trees / forests to absorb carbon dioxide
• specified pollution, for example, visual, noise, atmospheric (including dust), water (including river or drinking) with cause, e.g. gases / particulates from burning diesel
• large amounts of methane (natural gas) are used to provide energy
• energy / fuel needed for cracking and fractional distillation
• burning fuel releases carbon dioxide
• crude oil / natural gas contains locked up carbon
• crude oil is non-renewable 6
[11]
M4. (a) hydrocarbons or hydrocarbon 1
(b) (i) distillation 1
(ii) evaporation 1
(iii) condensation 1
(c) (i) bond 1
(ii) (C6H)
14
1
(iii) cracking 1
Page 30 of 40
(d) (i) poly(butene) allow with or without brackets
1
(ii) Advantage = energy is released do not accept more than one tick in the advantage column
1
Disadvantage = carbon dioxide is produced do not accept more than one tick in the disadvantage column
1 [10]
M5. (a) any four from: • (crude oil is) heated • to evaporate / vaporise / boil (the substances / hydrocarbons) • the column is hotter at the bottom or is cooler at the top • (vapours / fractions) condense • at their boiling points or at different levels.
marks can be taken from a diagram max 3 marks for reference to cracking allow fractional distillation allow vapours (enter the column) allow temperature gradient or (vapours) cool as they rise allow description e.g. vapour turns to liquid) allow they have different boiling points
4
(b) acid rain is caused by allow consequences of acid rain
1
sulfur dioxide or oxides of nitrogen second marking point is dependent on first marking point
1
they react with / are neutralised by calcium carbonate or limestone OR global warming is caused by carbon dioxide
carbon dioxide will react or dissolve in suspension of limestone allow greenhouse effect is caused by or allow consequences of global warming
1
Page 31 of 40
(c) (i) C2H4
must be formula ignore any name
1
(ii) a single bond between carbon atoms
would score 3 marks
1
other four bonds linking hydrogen atoms and C3H7 group plus two trailing /
connecting bonds 1
n at the bottom right hand corner of the bracket 1
(iii) has a shape memory or (a smart polymer) can return to original shape (when conditions change)
1 [12]
M6. (a) (i) D 1
(ii) B 1
(iii) A 1
(iv) E 1
(v) E 1
(b) (i) high temperature ignore hot / heat allow temperature quoted (range 300-900 °C)
1
catalyst or steam 1
(ii) C8H
18 smaller molecule
It = C8H
18
1
Page 32 of 40
therefore there are weaker intermolecular forces allow intermolecular bonds do not accept breaking covalent bonds / bonds
or
weaker intermolecular forces in C8H
18 (1)
allow intermolecular bonds
so less energy to break (1) 1
(c) add bromine water 1
turns (from orange / yellow / red / brown) to colourless or decolourises
do not accept discoloured ignore clear incorrect test = 0 marks
1
(d)
single C – C bond
1
four carbon-hydrogen bonds in place and two trailing bonds 1
structure in brackets and n at bottom right 1
[14]
M7. (a) Sulfur dioxide causes acid rain. 1
(b) red / orange / yellow do not accept any other colours
1
because sulfur dioxide (when in solution) is an acid 1
(c) (there are) weak forces (of attraction) do not accept any reference to covalent bonds breaking
1
between the molecules do not accept any other particles
1
Page 33 of 40
(these) take little energy to overcome award third mark only if first mark given
1
(d) Marks awarded for this answer will be determined by the Quality of Communication (QC) as well as the standard of the scientific response. Examiners should also refer to the information on page 5 and apply a ‘best-fit’ approach to the marking.
0 marks No relevant content
Level 1 (1 – 2 marks) A relevant comment is made about the data.
Level 2 (3 – 4 marks) Relevant comparisons have been made, and an attempt made at a conclusion.
Level 3 (5 – 6 marks) Relevant, detailed comparisons made and a justified conclusion given.
examples of the points made in the response
effectiveness
• W removes the most sulfur dioxide • D removes the least sulfur dioxide
material used
• Both W and D use calcium carbonate • Calcium carbonate is obtained by quarrying which will create scars on
landscape / destroy habitats • D requires thermal decomposition, this requires energy • D produces carbon dioxide which may cause global warming / climate change • S uses sea water, this is readily available / cheap
waste materials
• W product can be sold / is useful • W makes carbon dioxide which may cause global warming / climate change • D waste fill landfill sites • S returned to sea / may pollute sea / easy to dispose of
6 [12]
M8. (a) (i) mixture (of different substances) 1
(ii) boiling (points) 1
(iii) distillation 1
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(b) (i) combustion 1
(ii) (reactant)
oxygen allow correct formulae
1
(products) products in any order
carbon dioxide allow carbon or carbon monoxide
and water
allow water vapour or steam or hydrogen oxide 1
(iii) (burning sulfur) produces sulfur dioxide / S02
allow it / sulfur reacts with oxygen ignore sulfur oxide 1
causes acid rain 1
(c) (i) propane is a fuel 1
(ii) double bond drawn between carbon atoms do not allow any other bonds or symbols
1
(iii) orange to colourless 1
(iv) poly(pentene) allow polymer(s)
1 [12]
M9. (a) C6H
14
1
(b) A 1
(c) B 1
(d) C 1
(e) Propanol 1
[5]
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M10. (a) (i) (conical) flask 1
(ii) measuring cylinder / pipette / burette 1
(b) (i) any two from: • so anomalous results could be identified / ignored • so a mean / average could be taken • (to improve) accuracy
2
(ii) 19 1
(iii) increases / gets longer / gets bigger 1
(iv) anomalous / does not agree with other times for C10H22
1
(v) any one from: • shorter hydrocarbon used • volume of hydrocarbon too small • started timing late • stopped timing too early / when liquid left in funnel
must suggest why the result is lower than the others. allow the temperature was higher or the students used a wider funnel.
1
(c) (i) flammable 1
(ii) suitable safety precaution 1
reason that links the safety precaution to the hazard symbols eg: • wear gloves • (because) it is hazardous to health / harmful / toxic / irritant or • do not pour down sink or dispose of properly • (because) it is harmful to the environment / kills fish or • wear a mask or do it in the fume cupboard or a well-ventilated area • respiratory irritant
1
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(d) (i) points plotted correctly (within half small square) all six points correct scores 2 3, 4 or 5 points correct scores 1
2
smooth curve of best fit 1
(ii) point at 46 °C circled allow point furthest from the line as drawn
1
(iii) working shown on graph 1
value read from graph line drawn (within half small square) 1
(iv) the higher the temperature the lower the viscosity allow the higher the temperature the lower / shorter the time taken for 1 mark
2
non-linear or change gets smaller as temperature gets higher
answer relating temperature to time taken can score a maximum of 2 marks.
1
(v) identifying source of the error 1
method of avoiding the error eg: • the temperature will drop • insulate the funnel or • runs out before all added • put a tap on the funnel
1 [22]
M11. (a) A compound made from carbon and hydrogen (not mixture etc.) 1
(b) C5H
12
1
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(e) (i) Break down
by heat
(ii) Speeds up reaction
(iii) C8H
16
each for 1 mark 4
[6]
M12. (a) C5H
12
1
(b) Alkanes 1
(c) (3) CO2
1
(4) H2O
1
allow for 1 mark 4 CO2 + 3 H2O
(d) contains hydrogen and carbon 1
(hydrogen and carbon) only 1
(e) (diesel) produces more oxides of nitrogen
allow converse answers in terms of petrol 1
produces (more) particulate matter 1
produces less carbon dioxide 1
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(f)
2
[11]
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