Page 1 11 1 C1 Exam Revision (Higher) C1.1 The fundamental ideas in Chemistry Revision Questions Q1. A substance made of only one type of atom is called an element. The chemical symbols and positions of six elements in the periodic table are shown. Draw a straight line from each description to its correct symbol. Description Symbol Al A metal with a low density that does not corrode easily Fe It has properties similar to those of sodium, Na He It is a transition metal Li It is a noble gas O (Total 4 marks) Q2. The diagram shows an atom. (a) On the diagram, write the names of structures A, B, C and D. (4)
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11 1 C1 Exam Revision (Higher)
C1.1 The fundamental ideas in Chemistry Revision Questions
Q1. A substance made of only one type of atom is called an element.
The chemical symbols and positions of six elements in the periodic table are shown.
Draw a straight line from each description to its correct symbol.
Description Symbol
Al
A metal with a low density that does not corrode easily
Fe
It has properties similar to those of sodium, Na
He
It is a transition metal
Li
It is a noble gas
O
(Total 4 marks)
Q2. The diagram shows an atom.
(a) On the diagram, write the names of structures A, B, C and D. (4)
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(b) To which Group of the periodic table does this atom belong?
Q4. Atoms are made up of three main particles called protons, neutrons and electrons. Use the periodic table on the data sheet to help you to answer these questions.
(a) Sodium is in Group 1 of the periodic table.
(i) Why are potassium and sodium in the same Group of the periodic table?
Q5. This question is about oxygen atoms. The periodic table on the Data Sheet may help you to answer this question.
(a) (i) Oxygen atoms have 8 electrons. Complete the diagram to represent the arrangement of electrons in an oxygen atom. Use crosses (×) to represent the electrons.
(1)
(ii) Name the part of the oxygen atom that is labelled A on the diagram.
(a) What is the formula of propane? ........................................................................................ (1)
(b) (i) Draw a ring around the name of the particle represented by the symbols ○ and × in the diagram.
electron neutron proton (1)
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(ii) Draw a ring around the type of bonding that holds the atoms together in a propane molecule.
covalent ionic metallic (1)
(c) Under high pressure in the cylinder propane is a liquid. Liquid propane evaporates easily to form a gas when the tap on the cylinder is opened. Draw a ring around the correct answer in each box to explain why propane evaporates easily.
Propane has a high
low boiling point because it consists of
large
small molecules.
(1)
Q9. (a) Atoms are made of sub-atomic particles. Complete the six spaces in the table
Name of sub-atomic particle Relative mass Relative charge
(ii) Limestone contains calcium carbonate, CaCO3 Draw a ring around the correct gas in the box to complete the sentence.
The gas formed when calcium carbonate decomposes is
argon.
carbon dioxide.
nitrogen.
(1)
(c) The cement works starts to burn a different fuel. Local residents are concerned because more children are suffering asthma attacks. Residents have also noticed that parked cars are becoming dirty because of smoke particles from the chimney. The table shows the possible medical risk from smoke particles.
Particle size in mm Medical effect
Larger than 0.4 No medical risks known
0.3 and smaller Causes asthma attacks
0.2 and smaller May cause cancer
(i) Give two reasons why local residents are concerned about the cement works burning a different fuel.
Q3. A limestone quarry is in an area of natural beauty and near several villages. The company operating the quarry wants planning permission to build a new cement works in the quarry. The diagram shows some of the substances used and produced at a cement works.
(a) Limestone is mainly calcium carbonate, CaCO3. Write the correct number in the box to complete each sentence.
(i) The formula shows that calcium carbonate, CaCO3,
contains different elements. (1)
(ii) Calcium carbonate, CaCO3, contains a total number of atoms. (1)
(b) The company wants the new cement works because the nearest cement works is 100 km from the quarry. The company argues that a new cement works sited inside the quarry would reduce carbon dioxide emissions.
Suggest why the new cement works might reduce carbon dioxide emissions.
(ii) In the kiln the raw materials are heated to about 1500°C. The limestone (calcium carbonate) is broken down at this temperature. Complete the word equation for this reaction.
C1.3 Metals and their uses Revision Questions Higher
Q1. Iron is the main structural metal used in the world.
(a) The diagram represents the particles in iron, Fe.
Draw a ring around the correct word in the box to complete the sentence.
Iron is described as an element because all the
atoms
compounds
metals
are the same.
(1)
(b) Stainless steel is mostly iron.
The diagram represents the particles in stainless steel.
Use the correct words from the box to complete the sentences about alloys.
metal mixture molecule polymer smart structure
Stainless steel is an alloy because it is a ........................................................................... of iron, chromium and nickel. An alloy is made up of more than one type of ................................................................ . Stainless steel alloys are harder than iron because the different sized atoms added change the ............................................................................... . An alloy that can return to its original shape after being deformed is called a..................................................................... alloy.
(4)
(c) In the UK, we use about 1.8 billion steel cans every year but only 25% are recycled. Used steel cans are worth about £100 per tonne.
Recycling saves raw materials and reduces waste that would end up in landfill. Producing steel by recycling used cans saves 75% of the energy that would be needed to produce steel from iron ore. This also reduces carbon dioxide emissions.
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(i) Give two reasons, from the information above, to explain why recycling used steel cans is a good idea.
Q6. A student was trying to extract the metals from lead oxide and aluminium oxide. She heated each oxide with carbon in a fume cupboard as shown below.
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She was able to extract lead from lead oxide but not aluminium from aluminium oxide.
(b) Many industrial processes involve the removal of minerals by quarrying.
All quarrying has some effect on the environment and on people’s lives. Make comments about the social, economic, health, safety and environmental effects of quarrying.
Q8. Use the Reactivity Series of Metals on the Data Sheet to help you to answer this question. The table gives information about the extraction of some metals.
Metal Date of discovery Main source Main extraction method
Gold Known to ancient civilisations
In the Earth as the metal itself
Physically separating it from the rocks it is mixed with
Zinc 1500 Zinc carbonate Reduction by carbon
Sodium 1807 Sodium chloride Electrolysis
(a) Explain why gold is found mainly as the metal itself in the Earth.
Q2. 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)
Q3. The structural formulae of two saturated hydrocarbons are shown below.
Describe two ways in which they will differ in their physical properties.
(c) The simplest hydrocarbon is methane, CH4. Its structure can be represented:
Draw the structure of ethane, C2H6. (1)
Q5. Useful fuels can be produced from crude oil. Crude oil is a mixture of hydrocarbons.
(a) The table shows the boiling points of four of these hydrocarbons.
Hydrocarbon Boiling point in °C
methane, CH4 –162
butane, C4H10 0
pentane, C5H12 +36
decane, C10H22 +175
Tick ( ) two statements that are correct about these hydrocarbons.
Statement Tick ( )
decane has the largest molecules
pentane is a liquid at 40°C
methane and butane are gases at 20°C
methane has the highest boiling point
butane does not boil
(2)
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(b) Natural gas supplied to homes and schools is mainly methane. The diagram shows an apparatus to investigate the two substances produced when natural gas burns completely in air.
(i) Name the liquid that collects in the U-tube. ........................................ (1)
(ii) Name the gas that turns the limewater cloudy .................................... (1)
(c) Some crude oil contains sulfur. Petrol and diesel fuels are produced from crude oil.
The sulfur must be removed from these fuels before they are burned. Explain why.
Q8. Crude oil is a mixture of long-chain hydrocarbons. It is cracked to produce a mixture of smaller alkanes and alkenes. Among the gases formed are ethane and ethene.
(a) Write the structural formula for:
(i) ethane
(1)
(ii) ethene
(1)
(iii) Give an example of one chemical reaction which both ethane and ethene undergo.
(iv) Describe how to distinguish between ethane and ethene. Include a description of the practical method you would use and what you would expect to observe.
(b) Ethene may be polymerised to form a polymer. Give the name of the polymer and a use for it.
Name ............................................... Use ........................................................... (1)
Q9. Since 2000 there has been a lot more research into alternative, environmentally-friendly fuels for road transport. Several pollutants are found in the exhaust emissions produced when fossil fuels are used for road transport. Carbon monoxide (CO) interferes with the way that red blood cells carry oxygen. Carbon dioxide (CO2) increases the level of carbon dioxide in the atmosphere and causes global warming. Oxides of nitrogen (NOx) are produced at high temperatures when nitrogen and oxygen from the atmosphere combine. Sulfur dioxide (SO2) is produced when sulfur impurities in the fuel combine with oxygen in the atmosphere.Tiny particles of solids are produced when the fuel does not burn completely. This increases the level of particulates (PM10) in the atmosphere.
(a) Name the environmental effect caused by:
(i) oxides of nitrogen (NOx) and sulfur dioxide (SO2)
(b) Diesel obtained from crude oil is often called fossil diesel. Biodiesel can be made from many vegetable oils. One research project compared the exhaust emissions when fossil diesel or biodiesel were used as fuels.
Some of the relative amounts of these exhaust emissions are shown in the bar chart.
(i) Use your knowledge and the information above to explain the environmental benefits of using biodiesel as a sustainable, low pollution fuel.
This is because the life-cycle emission of carbon dioxide from biodiesel is less than that from fossil diesel.
Use your knowledge and the information above to explain why biodiesel’s contribution to global warming is considered to be much less than that of fossil diesel.
(c) There are millions of plastic bags in use. After use most of these plastic bags are buried in landfill sites. The amount sent to landfill could be reduced if the plastic bags: • could be reused • could be recycled by melting and making into new plastic products • could be burned to release energy
Use the information above and your knowledge and understanding to give the positive and negative environmental impacts of using these methods to reduce the amount of plastic bags sent to landfill.
(ii) The table gives information about monomers and the polymers made from them. Complete the table.
(3)
(Total 8 marks)
Q6. Known crude oil reserves are being used up rapidly. Crude oil is used to produce many useful fuels, such as petrol. One way to conserve crude oil reserves would be to increase the production of bio-fuels.
(a) Ethanol can be produced for use as a bio-fuel. Cars can be powered by ethanol or ethanol–petrol mixtures.
Sugar cane can be fermented to give a mixture of water (boiling point 100 °C) and ethanol (boiling point 78 °C).
(ii) Ethanol, C2H5OH, burns to release heat energy.
Complete the balanced symbol equation by writing in the formulae of the two products.
C2H5OH + 3O2 2......... + 3......... (2)
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(b) The cost of producing a bio-fuel, such as ethanol, by fermentation, is at least three times higher than the production cost of petrol. It costs less to produce ethanol from alkanes. In the production, the vapour of an alkane is passed over a hot catalyst.
Ethene is then converted into ethanol.
(i) What has happened to the hexane to produce ethene?
(a) The diagram shows some apparatus used to obtain oil from plant material.
Four parts of the apparatus are labelled, A, B, C and D.
Use the information in the diagram to complete the sentences.
Steam is made in part .
Oil from the plant material is vaporised in part .
Steam and oil vapour are condensed in part . (3)
(b) A student investigated a mixture of a plant oil and water.
(i) A mixture of the plant oil and water was shaken and left to stand for 10 minutes.
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Draw a ring around the correct answer to complete the sentence.
dissolves.
floats.
sinks.
The plant oil separates from the water because it
(1)
(ii) A mixture of the plant oil, water and egg yolk was shaken and left to stand for 10 minutes. The mixture did not separate.
Draw a ring around the correct answer to complete the sentence.
a compound.
an emulsion.
a fat.
The plant oil, water and egg yolk make
(1) (Total 5 marks)
Q3. Use the correct words from the box to complete the sentences.
higher hydrogen lower
oxygen saturated unsaturated
(i) Animal and vegetable oils that contain .................................. fats can be hardened. (1)
(ii) When oils are hardened with .................................. gas, a chemical change takes
place, producing margarine which has a .................................. melting point than
the original oil. (2)
(Total 3 marks)
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Q4. This information was taken from a label on a packet of crisps.
Main ingredients:
Potatoes, vegetable oil, Worcester sauce flavour,
colourings, flavourings, salt.
Nutritional information (per 100 g):
Energy 2040 kJ
Protein 6.5 g
Carbohydrate 55 g
of which sugars 3 g
Fat 27 g
of which saturates 9 g
unsaturates 18 g
Fibre 4.5 g
Sodium 1.2 g
Saturated fats are linked to heart problems. In order to claim that their crisps are healthy, the manufacturer keeps the proportion of saturated fats low.
(i) What type of fat contains double carbon carbon bonds?
(b) Saturated fats are linked to heart problems. Oils that are unsaturated help to prevent heart disease. A company wants to make a ‘healthy’ soft margarine.
The company tested the same volume of different vegetable oils by shaking each with three drops of iodine solution. The results are shown in the table.
Vegetable oil Time in minutes for the
colour of iodine to ‘disappear’
Olive oil 3.5
Peanut oil 3.0
Soya oil 1.5
Sunflower oil 1.0
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(i) Why does iodine react with the molecules in these oils?
Q6. An advert for crisps claimed that they are healthier because they are cooked in sunflower oil.
(a) A student found the following information about four oils that are used to make crisps.
Rapeseed oil Sunflower oil Olive oil Corn oil
Saturated fat (%) 6.6 12.0 14.3 14.4
Polyunsaturated fat (%)
29.3 63.3 8.2 51.3
Melting point (°C) +5 –18 –12 –15
One hypothesis is that oils are thought to be healthier if they are: • low in saturated fat
• high in polyunsaturated fat.
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(i) Use the table to decide which oil should be healthiest. Explain your decision by comparing this oil with other oils from the table that you think are less healthy.
Healthiest oil is .....................................................................................
(ii) These oils can be hardened by reacting them with hydrogen. A student said that hardening would make sunflower oil healthier. Is this student’s claim correct?
Q7. An advert for some crisps claims that they now contain only 30% saturated fat because they are cooked in sunflower oil. The crisp company used bromine water to compare percentage unsaturation of sunflower oil with four other vegetable oils, A, B, C and D.
Oil
Volume of bromine water added until the bromine colour just remains (cm3)
Percentage unsaturation
(%) Test 1 Test 2 Test 3 Average
Sunflower 25.4 28.0 27.0 26.8
A 13.0 14.0 15.0 14.0 35
B 23.2 11.2 24.0 23.6 59
C 19.9 21.1 20.2 20.4 51
D 9.5 8.8 9.3 9.2 23
(i) What is the range of percentage unsaturation for oils A, B, C and D?
Range = ................................................ % (1)
(ii) Describe and explain what happens to the first drops of bromine water that are added to these oils.
(b) Complete the sentences by writing in the correct words.
Recent evidence has supported Wegener’s idea.
The Earth’s .................................. and the upper part of the mantle are now thought to
be composed of tectonic plates.
Heat released by radioactive processes causes convection currents within the Earth’s
.................................. These convection currents cause the plates to move a few
centimetres per ................................... (3)
(Total 6 marks)
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Q3. (a) The diagram shows the layered structure of the Earth.
(i) Write in the boxes the name of layer X and the name of layer Y. (2)
(ii) The overall density of the Earth is about 5500 kg/m3. The average density of the rocks in the Earth’s crust is about 2800 kg/m3. What does this suggest about the material that makes up the lower layers of the Earth?
(b) In 1915, the scientist Alfred Wegener suggested that Africa and South America had once been joined but had since drifted apart. Evidence for his theory came from the animal fossils found in the two continents. The fossils are almost the same, although animals now living in Africa and South America are different. Other scientists did not agree with Wegener and suggested that a land bridge had once joined the two continents.
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How could scientists use the idea of a land bridge to explain the evidence put forward by Wegener?
(c) Scientists now think that the outer layer of the Earth is cracked into a number of large pieces called tectonic plates. The tectonic plates are moving very slowly. The lines on the diagram show the boundaries between the major tectonic plates.
(i) Explain why there are no major earthquakes in Britain.
Q6. (a) During the first billion years of the Earth’s existence, there were many active volcanoes. The volcanoes released the gases that formed the early atmosphere.
Describe how volcanoes caused the oceans to be formed.
(b) The atmosphere on Earth today is very different from the early atmosphere.
The pie chart shows the amounts of different gases in the air today. Choose gases from the box to label the pie chart.
argon carbon dioxide hydrogen nitrogen oxygen
(2)
(Total 4 marks)
Q7. For 200 million years the proportions of the different gases in the atmosphere have been much the same as today. Over the past 150 years the amount of carbon dioxide in the atmosphere has increased from 0.03% to 0.04%.
(a) Describe how carbon dioxide is released into the atmosphere:
Q8. Air is a mixture of gases and contains various pollutants. The gases are useful and can be separated by fractional distillation of liquid air. The table gives information about some of the gases in air.
Name of gas Formula Melting point in °C Boiling point in °C
Helium He –272.2 –269.0
Oxygen O2 –219.0 –183.0
Nitrogen N2 –210.0 –195.9
Argon Ar –189.0 –185.9
Carbon dioxide CO2 –78.5 –78.5
Water vapour H2O 0.0 100.0
To separate these gases:
• the air is filtered • water is removed first • carbon dioxide is then removed by absorption • the gases remaining are compressed and cooled to –200 °C.
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(a) The air is filtered before the gases are separated.
allow reaction 3 identified do not allow incorrect reaction ignore mixes, unless they state the correct product
• limestone / calcium carbonate / CaCO3 forms
allow marble / chalk
• water is lost / evaporates
it = plaster
allow moisture ignore dries
3
(b) (i) as the amount / volume of sand decreases the strength of the mortar increases
accept as sand decreases the mortar is stronger / harder to crack
allow as sand decreases the mortar increases
allow converse
ignore references to height of metal ball 1
(ii) any two from:
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• 400 / 5th result is anomalous
accept two results (36 and 37 / 400 and 500 / 4th and 5th) are almost the same accept result at 400 should be 42
• the interval between the others is similar or the interval is about 6/7
allow the other results fit a pattern / are on a straight line
• he has only one set of results
allow he has only done it once
ignore reliable 2
[7]
M7. (a) (i) clay
for one mark
(ii) calcium oxide / quicklime / CaO
for one mark
(iii) sensible answers such as cost of fuel etc. / accept a wide range of appropriate answers
for one mark 3
(b) sand gravel (owtte) e.g. crushed rock water
any two for 1 mark each 2
[5]
M8. (i) (hot air) gives faster reaction makes coal burn faster (provides air / oxygen to help to) allow the coal to burn / helps combustion flushes out the waste / gases / carbon dioxide
any one for 1 mark 1
(ii) decomposition of limestone yields carbon dioxide (owtte) the combustion / burning of coal produces carbon dioxide (owtte)
each for 1 mark 2
[3]
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C1.3 Metals and their uses Higher Answers
M1. (a) atoms
1
(b) mixture 1
metal 1
structure 1
smart 1
(c) (i) any two from:
• saves raw materials / iron ore
• saves energy / fuels
accept cheaper / saves money
• make new / useful items
• make money / it is economic
• reduces pollution
allow less harmful for the environment
• decreases cost of steel cans
• reduces carbon dioxide emissions
• decreases waste materials / use of landfill 2
(ii) any one from:
• provide information / education of the need to recycle
• legislate against / charge for waste
• reward / pay people to recycle
accept fine people for not recycling
• put labels on the cans
• provide recycling bags / bins / areas 1
[8]
M2. (a) (i) any one from:
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• iron ore is a limited resource / non-renewable
• iron is in high demand
• provide jobs
• economic advantage 1
(ii) any two from:
• would damage (wildlife) habitats / countryside / greenfield sites
• extra traffic
• visual (pollution) / eyesore
• noise (pollution) / sound (pollution)
• dust (pollution)
• river (pollution)
• carbon dioxide (from traffic) / adds to greenhouse effect / global warming
• damage roads / buildings by vibrations / shockwaves 2
(b) (i) carbon monoxide / carbon
accept formulae CO / C 1
(ii) atoms
accept (particles) are all the same (size) / type for one mark
1
are all the same (size) / type 1
(iii) any two from:
• impurities / carbon / different (sized) atoms or elements or metals
• changes the structure / disrupts the pattern or layers
• prevents layers sliding over each other
• it is an alloy 2
[8]
M3. (a) good (electrical) conductor
allow low reactivity / resistance to corrosion
do not accept heat conductor 1
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(b) a mixture of metals
accept contains more than one type of metal 1
(c) (i) any one from:
• eyesore
• destruction of habitats
• pollution of water
• dust pollution
• noise
• traffic pollution 1
(ii) acid rain
allow sulfur dioxide is a pollutant
1
(d) (i) running out of copper (ores) 1
(ii) any two from:
• any specific example of using less copper
• reuse / recycle
allow do not throw copper / brass away
• use low-grade copper ores
• use other metals / materials in place of copper 2
[7]
M4. (a) (an alloy) that can return to its original shape (after being deformed / bent / twisted)
accept (on heating / cooling) it returns to its shape
1
(b) any two from:
• brass / it is a mixture
accept brass / it is not pure
• zinc changes structure / disrupts patterns or layers
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• copper metal atoms / layers able to slide over each other
accept zinc prevents atoms / layers sliding over each other 2
(c) (i) oxygen / O2 / O 1
(ii) lead remains (in furnace) because of its high boiling point 1
zinc boils / evaporates (out of furnace) because of its low boiling point 1 if neither mark awarded then allow 1 mark for different boiling points
ignore references to melting points 1
[6]
M5. (a) (very) small percentage / amount (in the Earth’s crust)
any indication that there is a small amount, eg not much (left) accept rare (elements) / rarer accept not commonly found ignore cannot find easily ignore hard to extract
1
(b) (i) oxygen / O / O
do not accept O
1
(ii) any one from:
• potassium / K • sodium / Na • calcium / Ca • magnesium / Mg
symbols must be correct write name and incorrect symbol, ignore symbol
1
(c) (i) heating (with) or hot air blown into furnace
accept high temperatures or (very) hot 1
carbon / carbon monoxide / coke / coking coal
do not accept coal / charcoal accept balanced equation only
orcarbon reacts with O2 or carbon / coke burning (1)
accept balanced equation only CO / CO2
CO reacts with the ore (1)
for naming the reducing agent 1
(ii) cost of melting ore / electricity makes aluminium expensive (owtte)
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or (large amount of) electricity used or because you have to use electrolysis or aluminium is higher in the reactivity series or aluminium is harder to reduce or unable to reduce with carbon or the cost of purifying the bauxite
do not accept harder to extract / produce more energy is not enough
1
[6]
M6. (i) idea that:
carbon is above lead in the reactivity series } NOT
for 1 mark
carbon is below aluminium in the reactivity series } OXIDE
for 1 mark
carbon can remove oxygen from/reduce lead oxide or cannot remove oxygen from aluminium oxide not aluminium more reactive than lead
for 1 mark
OR similar ideas in comparing bond strengths 3
(ii) (carbon + lead oxide) →*lead + *carbon dioxide
each for 1 mark
accept correct formulae CO2 and CO NOT carbon oxide
2
[5]
M7. (a) any two points one mark each
accept comparison between aluminium and iron
aluminium has:
• a low density
accept lighter or fewer pylons
• a good conductor of electricity
• does not corrode or rust
do not accept does not react with air
do not accept last longer 2
OR
• iron has:
• high density
• is a less good conductor (of electricity)
• rusts or reacts with air
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(b) any 5 from:
• employment of people or cost of employment
• depletion or use of resources
do not accept depletion here
• cost of energy resources
• cost of machines or buildings
• pollution by noise from traffic or quarrying
• air pollution by dust or traffic fumes
• danger of traffic on roads
• damage to landscape (eyesore)
• damage to habitats of wildlife
• lowers the value of houses nearby
• subsidence or vibration can affect roads or houses
• providing raw materials
do not accept danger or falling in 5
[7]
M8. (a) unreactive / near bottom of reactivity series
1
(b) carbon more reactive / higher up reactivity series 1
(c) very reactive / near top of reactivity series 1
cannot use displacement methods / can only be extracted by electrolysis / had to wait discovery of electricity
1
[4]
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C1.4 Answers
M1. (i) carbon and hydrogen only or compound of
for 1 mark each 2
(ii) single bonds only or no double bonds etc or contains maximum number of hydrogen atoms
for 1 mark 1
(iii) molecules of similar chain length similar boiling points limited range of boiling points etc
M3. B will have higher melting point higher boiling point be less volatile be more viscous (allow less flammable)
any two for 1 mark each [2]
M4. (a) the more C atoms the higher the b.pt./temperature Allow just higher. Not answer based on melting point
for 1 mark 1
(b) (fractional) distillation/fractionation
for 1 mark 1
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(c)
must include H atoms and lines not CH3 – CH3
for 1 mark 1
[3]
M5. (a) decane has the largest molecules 1
methane and butane are gases at 20 °C 1
(b) (i) water 1
(ii) carbon dioxide 1
(c) sulfur dioxide is produced when sulfur burns 1
therefore sulfur must be removed from these fuels because sulfur dioxide causes acid rain
1
[6]
M6. (a) (i) X and Y
both needed 1
(ii) Z 1
(iii) X 1
(b) unsaturated / alkenes / those with double (C = C) bonds 1
[4]
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M7. (a) each bar correct height (2 bars) to less than ½ square
1 mark for each
both bars correctly labelled (in relation to size of bars)
for 1 mark 3
(b) less
gains 1 mark
but a lot less / much less / 18 times less or more if referring to coal
gains 2 marks 2
(c) (i) carbon sulphur
for 1 mark each 2
(ii) ideas that
• at high temperatures, (produced when fuels burn)
• nitrogen and oxygen from atmosphere combine / react
for 1 mark each 2
M8. (a) (i)
do not credit CH3CH3
1
(ii)
do not credit C2H4
1
(iii) burn or react with oxygen or combustion or oxidation
accept react with chlorine 1
(iv) bubble each gas through (test tube containing) bromine water
accept add bromine (water to gas collected) or burn 1
ethene decolourises it or turns the brown colourless
do not accept makes it go clear 1
ethane does not affect it or leaves it brown 1
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(b) both the correct name and use are required for the mark poly (ethene) or polythene; any soft or pliable plastic article or any suitable harder plastic item
accept polyethene or polyethylene 1
M9. (a) (i) acid rain
accept consequences of acid rain
allow asthma / bronchitis
ignore toxic gas 1
(ii) global dimming
accept dimming alone 1
(b) (i) sustainable:
maximum two from:
• crops (that produce oil) can be grown in most places owtte
• renewable
• use less fossil fuels / diesel
• use (refined) waste oils
low pollution:
maximum two from:
ignore references to CO2 here
• most emissions are lower or any two named emissions from CO / SO2 / PM10 are lower
• much / lot less SO2 emissions (than the others) owtte
• accept spillages / waste is biodegradable
• less new CO2 or (more) carbon neutral 3
(ii) plants / photosynthesis use carbon (dioxide) from the air* 1
it / biodiesel releases carbon (dioxide) from plants / crops / photosynthesis*
(*) allow 1 mark for biodiesel is (more) carbon neutral 1
(fossil) diesel releases ‘locked up’ / new carbon (dioxide) / doesn’t absorb CO2 / absorbed it millions of years ago
1
[8]
Page 76
C1.5 Answers
M1. (a) (i) the greater the number (of carbon atoms), the higher its boiling point
do not accept hydrocarbons for carbon atoms
allow converse
allow melting point 1
(ii) accept answers in the range 344 to 350 1
(iii) 216 1
(b) (i) EITHER
shortage of petrol or demand for petrol is higher than supply
diesel is in excess or supply of diesel is higher than demand 1
OR
petrol low supply and diesel high supply (1)
petrol high demand and diesel low demand (1)
petrol / diesel not specified = max 1 1
(ii) any one from:
• use diesel to make petrol
accept crack diesel or description of cracking
• make diesel cheap(er) (than petrol) or make petrol more expensive
accept lobby the government to reduce the tax on diesel / increase tax on petrol
• mix ethanol with petrol
ignore biodiesel 1
[6]
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M2. (a) catalyst or speeds up the reaction (owtte)
accept lowers activation energy not just helps reaction to take place ignore increased surface area
1
(b) C8H18
allow H18C8
must be upper case do not accept powers
1
(c) B because it is a gas or because it has small molecules or because they are small
position and reason for mark allow it has a lower / very low boiling point than A ignore references to solubility accept does not condense do not accept light molecules or bubbles into B do not accept it is small
1
(d) breakdown of a substance (owtte)
do not accept decompose unqualified 1
by the action of heat (owtte) 1
(e) Quality of written communication
if the written communication makes sense and it is in context then award Q mark
Q Q 1
large to small molecules or scientific word that implies smaller, e.g. alkene / ethane / petrol
any name or formula of alkane / alkene smaller than decane 1
either advantages of smaller molecules or disadvantages of larger molecules e.g. hydrocarbons with large molecules are limited in their usefulness
or converse for smaller molecules 1
large hydrocarbon molecules do not ignite easily / do not flow easily / are not very volatile
or converse for smaller molecules
more large hydrocarbon molecules are produced than are needed
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or converse for smaller molecules
smaller molecules are useful as fuels
alkenes / products can be used to make polymers
(f) (fractional) distillation
accept fractionation accept good description do not accept just diagram
1
[9]
M3. (a) (fractional) distillation/fractionation
for 1 mark 1
(b) (i) cracking/decomposition
for 1 mark 1
(ii) polymerisation/addition reaction
for 1 mark 1
(c)
(Must have H atoms)
for 1 mark 1
(d) contains only/all single bonds no double bonds contains maximum number of H atoms carbon atoms bonded to 4 other atoms (not 4 H atoms) will not undergo addition reactions
any 1 for 1 mark 1
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(e) (n must be on (right))
= 2 marks
(n on left = 1 mark)
= 2 marks
= 1 mark
= 1 mark
(Double bond loses both marks)
= 0 marks
OR
= 2 marks
Page 80
(for both a minimum of 4 carbon atoms)
= 1 mark
= 2 marks
= 1 mark
= 1 mark 2
[7]
M4. (a) alkanes 1
catalyst 1
substances must be in the order shown
(b) many (ethenes/monomers) 1
bond/join together 1
allow ethenes / monomers bond / join together to form very large molecules for 2 marks
(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.
No relevant content. 0 marks
Page 81
There is a brief description of a positive and a negative environmental impact involved with one or more methods used to reduce the amount of plastic bags sent to landfill.
Level 1 (1–2 marks)
There is some description of both positive and negative environmental impacts involved with at least 2 methods used to reduce the amount of plastic bags sent to landfill.
Level 2 (3–4 marks)
There is a clear, balanced and detailed description of both a positive and a negative environmental impact of using each of the 3 methods used to reduce the amount of plastic bags sent to landfill.
Level 3 (5–6 marks)
examples of the chemistry points made in the response
reuse: reuse means less bags used so:
positive environmental impact
• saves raw materials / crude oil
• saves energy
• cuts down on CO2 emissions
• less global warming
negative environmental impact
• could cause litter
• could still be sent to landfill
recycle: bags bought can be recycled so:
positive environmental impact
• used to make new plastic bags / objects
• saves raw materials / crude oil
• saves energy compared to producing plastic bags from crude oil
• cuts down on CO2 emissions
• less global warming
negative environmental impact
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• collection point sites cause an eyesore / litter problem
• transportation to recycling plant releases carbon dioxide / causes global warming
burn: bags can be burned so:
positive environmental impact
• could provide energy for heating buildings
• could provide energy for generating electricity
negative environmental impact
• increases CO2 emissions
• increases global warming
• could release toxic gases
does not conserve raw materials / crude oil [10]
M5.(a) (i) bonds / pair of electrons / shared electrons
for one mark 1
(ii) saturated since it has single bonds / no double bonds / no multiple bonds / maximum number of atoms attached
for one mark 1
(iii) sensible answer (e.g. it is harmful) or better solvent could be used on expanded polystyrene or foam
for one mark 1
(b) (i) simply writing monomers form / react to form polymers gains no mark
Page 83
monomers join / bond / combine / link to form polymers = 1 mark the mark is for the idea of joining to gain the second mark the idea of the relative size of monomer and polymer is required small molecules join to form a polymer (2 marks) many monomers join to form a polymer (2 marks) monomers join to form a large molecule / long chain (2 marks) many molecules join together (2 marks)
for 1 mark each 2
(ii) polyethene / poly(ethene) / polythene
don’t worry too much about the exact positioning of the C6H5 at the end of the bond
placement of linking bonds inside / outside brackets is not important must have n
for 1 mark each [8]
M6. (a) (i) by (fractional) distillation
accept a description of the distillation process (heat and how separation works) eg heat and condense accept boil / vapourise etc for heat
or
fractionation 1
(ii) CO2
note the order of these products must be correct 1
H2O
Page 84
wrong way round = 1 mark 1
(b) (i) (hexane) has been broken down (into smaller hydrocarbons / molecules) 1
(c) candidates must include both sugar cane and crude oil in their evaluation and both an advantage and a disadvantage to gain full marks. if they do not then the maximum mark is three
any four from:
advantages of using sugar
• country has no wealth to buy (large quantities of) crude oil
not ‘expensive’ alone
• country has limited technological development
or
underdeveloped / third world country
• able / suitable climate to grow sugar cane
• enough land to grow sugar cane / land cannot be used to grow food / deforestation
• sugar is a renewable source
or
crude oil is a non-renewable resource / finite resource / limited resources
• CO2 / carbon neutral
advantages of using alkanes:
• economic costs are low
• continuous process
• country has large oil resources
Page 85
• country has oil refineries / cracking plants
• very pure product
• faster process 4
[10]
Page 86
C1.6 Answers
M1. (a) (i) pressing 1
(ii) dissolve 1
(b) bromine 1
(c) temperature needs to be high / above 100 °C
allow melting point 1
or (sunflower oil has a) high(er) boiling point
or boiling point of water is not high enough
any one from:
• remove water / make potato crisp(er)
accept water makes potato soft / soggy
• adds / gives flavour 1
[5]
M2. (a) D 1
C 1
A 1
letters must be in the order shown
(b) (i) floats 1
(ii) an emulsion 1
[5]
Page 87
M3. (i) unsaturated 1
(ii) hydrogen 1
higher 1
[3]
M4. (i) (poly)unsaturated
accept monounsaturated 1
(ii) (turns) colourless or colour disappears / decolourises
do not accept clear 1
stays the same colour / orange / no change
allow yellow-orange / orange-brown / red-orange 1
(iii) (react) with hydrogen / H2 / hydrogenation 1
any one from:
• heated / 60 °C
• catalyst / nickel 1
[5]
M5. (a) (i) water and oil do not mix / are immiscible
ignore density 1
or
don’t dissolve each other
ignore emulsifier alone 1
(ii) any two from:
• emulsifier
• forms an emulsion
accept description of an emulsion
• holds the two components together
accept stops them separating / they mix
allow bonds / binds for holds
• by lowering the surface tension
accept a description of how an emulsifier works for two marks eg ‘tadpole’ diagram or dispersal of oil drops
2
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(b) (i) (because they contain) a double (carbon carbon) bond
accept unsaturated
ignore poly or mono 1
(ii) results suggest sunflower oil is best
or
‘the one that took the least time’ 1
because (sunflower oil) has the highest amount of unsaturation / most double bonds / least saturated
ignore uses up I2 most quickly
second mark is dependent on first 1
(c) (i) any one from:
• have a higher melting point than (vegetable) oil
• are solid at (room temperature) / hardened / harder
accept useful as spreads or doesn’t soak into bread
sunflower (oil) is healthiest because it has less saturated fat than both olive (oil) and corn (oil)
or
rapeseed (oil) is healthiest because it has the lowest value of saturated fat compared with the other oils
1
sunflower (oil) is healthiest because it has the highest value of polyunsaturated fat compared with all the other oils
Page 89
or
rapeseed (oil) is healthiest because it has more polyunsaturated fat than both olive (oil) and corn (oil)
1
no mark for the choice of oil
accept the use of values from the table for these comparisons
(ii) no, because hydrogen adds to the unsaturated fat or no, because hydrogen reduces the number of carbon–carbon double bonds
accept no because reacting with hydrogen increases number of single bonds
1
therefore there will be less polyunsaturated fat
accept therefore there will be more saturated fat 1
(b) molecules in egg yolk act as emulsifiers
accept lecithin molecules act as emulsifiers 1
because molecules in egg yolk have a ‘head’ which dissolves in / attracted to water
accept because molecules in egg yolk are hydrophilic 1
because molecules in egg yolk have a ‘tail’ which dissolves in / attracted to oil
accept because molecules in egg yolk are hydrophobic 1
[7]
M7. (i) 23 to 59
accept 36 1
(ii) decolourise or (orange to) colourless
ignore discolours / fades
do not allow oil decolourises 1
(because bromine reacts with the) (carbon) double bond
ignore alkenes or reference to unsaturation 1
(iii) any one from:
• an anomalous result (11.2) / Test 2
accept (= 23.6)
Page 90
• 11.2 / Test 2 is ignored when averaging
accept average of tests 1 and 3 1
(iv) unsaturation 67%
average was less than it should be / only 26.8 cm3
1
(this means there is) 33% saturated fat
it should have been 28.0 cm3 to give a percentage of 70% 1
[6]
C1.7 Answers
M1. (a) Layer A = crust / tectonic plates / (not named type of rock) Layer B = mantle / magma
each for 1 mark 2
(b) Layer C is liquid / molten (accept mostly liquid) but layer D is solid Layer D is more dense than layer C. / accept they have different densities Layer D is hotter than layer C. / accept they have different temperatures (Do not accept hardness / viscosity)
any one for 1 mark 1
[3]
M2. (a) (i) old animals / fossils / rocks match (when the continents are put together)
or (continents) fit together
ignore ‘they are the same shape’ 1
(ii) any two from:
• continents / plates cannot move (thousands of kilometres)
accept the continents / plates are attached to the Earth or continents / plates cannot drift / float
• modern / new animals are different
• a land bridge (could explain the matching fossils / rocks)
ignore ‘no evidence’ ‘no proof’ ‘no reputation’ 2
(b) crust
allow lithosphere 1
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mantle 1
year 1
[6]
M3. (a) (i) X – mantle 1
Y – inner core
do not accept solid core 1
(ii) different to the crust or contains a lot of (heavy) metals
accept iron and nickel for metals 1
higher (average) density or denser
density higher than 5500 (kg/m3) gets 2 marks 1
(b) animals were able to move from one continent to the other 1
(ii) 1. rock is heated / subducted (owtte) / close to magma / melted
Page 94
1. rock is decomposed / carbon dioxide released through volcanoes
for 1 mark each 2
(b) carbon dioxide reacts / dissolves in sea-water / dissolves in rain water insoluble carbonates / calcium carbonate are / is formed carbon dioxide turned into shells / coral / limestone / chalk / sediments also soluble hydrogencarbonates (calcium / magnesium) are formed photosynthesis by plants
any three for 1 mark each 3
(c) (i) sea unable to absorb all the extra carbon dioxide being produced more trees being cut down / deforestation increased burning of fuels / more cars / more industry (not more people)
any one for 1 mark 1
(ii) global warming / greenhouse effect or effects such as melting ice caps / rising sea levels / climatic change / more deserts (not changes to ozone layer)
for one mark 1
[9]
M8. (a) to remove solid / dust particles 1
(b) because at –200 °C both (water and carbon dioxide) are solids 1