Web view• oil and gas also contain hydrogen / contain more hydrogen atoms than carbon atoms ......

M1. (a) B because it contains more of the light fraction)1

Quantitative answer e.g. B has 30%,A has 20% / 10% more / 1.5 times more

1

(b) (i)

1

(ii) heat1

catalystif neither mark gained allow cracking for 1 mark

1[5]

M2. (a) both bars correct height_ (to better than half a square) 1 mark for both

both bars correctly labelled(w.r.t. relative height_s if these incorrect)

for 1 mark2

(b) a lot less / much less / 18 times less (converse must specify coal)gains 1 mark

1

(c) ideas that

• at high temperatures (produced when fuels burn)

• nitrogen and oxygen from air / atmosphere combine / reactor nitrogen from air / atmosphere oxidises

for 1 mark each2

(d) ideas that

• coal produces most carbon dioxide / more CO2 than gas / oil

• because coal is (mostly) carbon

• gas produces less carbon dioxide than coal / oil

• oil and gas also contain hydrogen / contain more hydrogen atoms than carbon atoms / also produce water

any three for 1 mark each3

(e) sulphurfor 1 mark

2[9]

M3. (a) • vertical axis appropriately scaled[i.e. using more than half the grid]

• all three points correctly plotted* (to < ½ a square)

• reasonably straight line drawn through points (to < half a square)*[*credit both these marks for bars correctly drawn sincediscontinuous variable]

each • for 1 mark

x [If points incorrectly plotted credit 1 mark for the best fit straightline or curve but not point-to-point]

3

(b) 44 (atomic units)for 1 mark(e.c.f. i.e. credit consistent with candidate’s graph)

1

(c) hydrocarbons / alkanesfor 1 mark

1

(d) C2H6

C5H12

each for 1 mark

[NB figures must be subscripted]2

[7]

M4. (a) nitrogen / N2[Do not allow N or N2] for 1 mark

(b) heatfor 1 mark

(c) carbon dioxide / CO2

for 1 mark[3]

##

(a) Compound A has fewer C atomsor Compound B has fewer H atoms

Compound A has C = C/double bondor Compound A is unsaturated

each for 1 mark(accept converse i.e compound B has

not ...)2

(b) Compound A is reactiveor can be used to make many substancesor can be used in polymerisation/making plastics/named plasticor can be used as a fuel

any one for 1 mark1

[3]

M6. (a) smaller, more useful molecules more reactive (molecules)/(molecules) used to make plastics more easily ignited/better fuels produces unsaturated compounds/alkenes

any two for 1 mark each2

(b)

gains 1 mark2

but

gains 2 marks

(c) (i)

for 1 mark1

(ii) poly(propene)(N.B. brackets not required; allow “polypropylene”)

for 1 mark1

[6]

M7. (a) ideas that it is a

• compound of metal/metal oxide/combined (NOT mixed) cpd/named cpd O2-/S2-/CO3

2- etc

• found naturally/in rocks/in Earth’s Crustfor 1 mark each

2

(b) reduction (accept smelting/refining but not electrolysis) for 1 mark

1

(c) One example. Al or above in Reactivity Seriesie Group I or II metals NOT Pb/Cu or compounds

for 1 mark1

[4]

M8. B will have higher melting point

higher boiling pointbe less volatilebe more viscous (allow less flammable)

any two for 1 mark each[2]

M9. (a) C=Cdo not accept C2H4

1

four Hs only, two attached to each carboncredit CH2CH2 for two marks

1

(b) C3H8 + 5O2 → 3CO2 + 4H2Otwo correct formulae LHS

1

can be in either ordertwo correct formulae RHS

1

can be in either ordercorrectly balanced, consequentialmarking allowed for 10 O

1[5]

M10. (a) Substance Use

A any pair fromaward one mark for a correctuse for an incorrect fuel

methane or fuel

natural gasor refinery gas

ethane fuel or making ethene for polymerisation

propane bottled or camping gas or fuel

accept relevant trade names e.g. Calor Gas2

butanebottled or camping gas orfuel or lighter fuel

B any pair from

petrol or gasoline fuel for carsaccept car enginesdo not credit just cars

naptha petrol or chemicals or feedstock or solvent

paraffin orkerosene heating fuel or aviation fuel

accept jet or aircraft fuel2

C any pair from

naptha petrol or chemicals or feedstock or solvent

paraffin orkerosene heating fuel or aviation fuel

diesel or diesel oilor (light) gas oil vehicle fuel or heating fuel

(lubricating) oil

lubricating or oiling qualified, eg. oiling a gate

fuel oil

industrial or heating fuel

heavy gas oil

fuel for stationary or slow speed diesel engines

2

(b) CO2 and H2Oboth required

1[7]

M11. (a) (i)

do not credit CH3CH3

1

(ii)

do not credit C2H4

1

(iii) burn or react with oxygen or combustion or oxidationaccept react with chlorine

1

(iv) bubble each gas through (test tube containing) bromine wateraccept add bromine (water to gas collected) or burn

1

ethene decolourises it or turns the brown colourlessaccept ethene burns with smoky flamedo not accept makes it go clear

1

ethane does not affect it or leaves it brownaccept ethane burns with clear flamenote carefully the spelling of ethene and ethane

1

(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 polyethylene1

[7]

M12. (a) (i) fractional distillationboth words required accept fractionation

1

(ii) any one from

ethane

propane

butane1

(b) (i) carbon dioxide1

water (vapour)

accept steam do not credit symbols

1

(ii) carbon monoxideaccept CO do not credit soot or carbon oxide

1[5]

M13. (a) carbon1

hydrogenany order

1

(b) fractional1

distillationaccept description• heat or evaporate / boil (1mark)• separated when they condense or by boiling points (1 mark)

1

(c) alkenesaccept names or unsaturated hydrocarbons

1[5]

M14. (a) all plots correct

3 or 2 plots correct gains 1 mark2

all sectors correctly labelled1

(b) (i) (fractional) distillation1

(ii) gases1

(iii) bitumen1

[6]

M15. (a) hydrocarbon1

(b) thermal decomposition / cracking1

(c) (i) making polymers / poly(e)theneaccept plastic (bags)

1

(ii) fuel1

[4]

M16. (a) the higher the boiling point, the greater the number of carbon atoms

1

(b) volatility / viscosity / runnyness / flammability / smokiness / amount ofoxygen needed for burning / melting point

do not credit how heavy it is / how it burns1

(c) hydrogen and carbon (both)allow H and C (upper case)

1[3]

M17. (a) hydrocarbon is a compoundnot mixture not substance

1

containing carbon and hydrogenaccept of the elements carbon and hydrogenaccept of carbon and hydrogencontains hydrogen and carbon only (2)

1

(b) (i) any order

carbon dioxideaccept CO2

exact formulae2

water 1accept H2Onot carbon in one box and dioxide in second box (0)ignore any attempt to ‘balance’ the equation

(ii) it is poisonousaccept toxiccan kill youaccept any reasonable descriptionof its effect on red blood cells or onhaemoglobin in terms of reducingoxygen transportnot can explode, harmful,dangerous, flammable

1[5]

M18. (a) any three from

carbon (atom) spine / chainaccept idea of ‘backbone’ of carbon (atoms)

surrounded by hydrogen (atoms)accept idea of only bonded to hydrogen (atoms)

3

single (covalent) bonds between carbon atomsaccept no double bonds

saturated (hydrocarbons)

(general formula) CnH2n+2

(b) many small molecules/ monomersaccept many unsaturated molecules or alkenes

1

join together to form a large / long molecule / polymer1

[5]

M19. (a) low1

hydrogen1

(b) any three from

• flameaccept it is a blue / yellow colour

• reacts with oxygenaccept burns in oxygen / bonds broken

• carbon dioxide carbon monoxide formsaccept CO2 arco / bonds forming in CO2/CO and H2Obonds forming 1 mark maxaccept an oxide of hydrogen or H2O

• water (vapour) formsaccept heat or light released / temperature increase / exothermic

• energy released3

[5]

M20. (a) (i) bonds / pair of electrons / shared electronsfor one mark

1

(ii) saturated since it has single bonds / no double bonds / no

multiplebonds / maximum number of atoms attached

for one mark1

(iii) sensible answer (e.g. it is harmful) or better solvent could be used on expanded polystyrene or foam

for one mark1

(b) (i) simply writing monomers form / react to form polymers gains no markmonomers join / bond / combine / link to form polymers = 1 markthe mark is for the idea of joiningto gain the second mark the idea of the relative size of monomer and polymer is requiredsmall 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 each2

(ii) polyethene / poly(ethene) / polythene

don’t worry too much about the exact positioning of the C6H5 atthe end of the bond

placement of linking bonds inside / outside brackets is not importantmust have n

for 1 mark each3

[8]

M21. (i) C8H18

for one mark1

(ii) mixturefor one mark

1

(iii) fractions moleculesatomsevaporated condensed

in this order for 1 mark each5

[7]

M22. (a) combustionfor one mark

1

(b) Bfor one mark

1[2]

M23. (a) hydrogen and carbonfor 1 mark

1

(b) (i) the oil is evaporated / boiled / liquid converted to gas / vaporised

oil is condensed/changed back to liquid/cooled below boiling point (not just cooled)

liquids of different boiling points condense at different levels /fractions with lower boiling points form near the top /boiling point linked to chain length or Mr

each for 1 mark3

(ii) Assume they mean naphtha unless they say otherwise.smaller molecules/contains less atoms/lower boiling point/more volatile/less bonds to break/lower activation energy

If the answer is given the opposite way around then diesel must be specified.

any one for 1 mark1

(iii)

correct number of atoms = 1correct number of bonds (attached to correct atoms) = 1Accept diagrams which show electrons correctly.CH3CH2CH2CH2CH2CH2CH3 = 1

for 2 marks2

[7]

M24. (a) the more C atoms the higher the b.pt./temperatureAllow just higher. Not answer based on melting point

for 1 mark1

(b) (fractional) distillation/fractionationfor 1 mark

1

(c)

must include H atoms and lines not CH3 – CH3

for 1 mark1

[3]

M25. (a) hydrocarbonsfor 1 mark

1

(b) less carbon atoms / smaller moleculefor 1 mark

1[2]

M26. (a) hydrocarbonsfor 1 mark

1

(b) less carbon atoms / smaller moleculefor 1 mark

1[2]

##

(a) (i) (fractional) distillation/fractionationfor 1 mark

1

(b) (i) cracking/decompositionfor 1 mark

1

(iii) polymerisation/addition reactionfor 1 mark

1

(c)

(Must have H atoms)for 1 mark

1

(d) contains only/all single bondsno double bondscontains maximum number of H atomscarbon atoms bonded to 4 other atoms (not 4 H atoms)will not undergo addition reactions

any 1 for 1 mark1

(e)

(n must be on (right))= 2 marks

= 2 marks

= 1 mark

= 1 mark

(Double bond loses both marks)= 0 marks

OR

= 2 marks

= 1 mark

= 2 marks

= 1 mark

= 1 mark2

[7]

M28. (a) C2H4

1

H H HH C C C H H H H

Accept even if in wrong columns1

(c) (i) polythene or poly(ethene)1

(ii) addition1

[4]

##

(a) fume cupboardplastic gloves (only one tick)

for 1 mark1

(b) (i) plotting points (allow ± 0.5 units either vertically or horizontally)(all correct = 2) (3 correct =1)curve (not joined with straight lines. Must be very closeto all points. One line only) (1 mark)

gains 3 marks3

(ii) as read from graph (±0.5 units) – points must be joined

for 1 mark1

(iii) decreases, gets less, quicker for 1 mark

1

(c) (i) flows, moves, passes through (not rubbing/moving ofengine parts)

for 1 mark

less etcfor 1 mark

2

(ii) parts rub against each otherincreases wear of engine partsdamages the oilengine seizesoverheating of engine (not burns or blows up)(not just ‘damage’)

any 1 for 1 mark1

[9]

M30. (i) carbon and hydrogenonly or compound of

for 1 mark each2

(ii) single bonds onlyor no double bonds etcor contains maximum number of hydrogen atoms

for 1 mark1

(iii) molecules of similar chain lengthsimilar boiling pointslimited range of boiling points etc

any 1 for 1 mark1

[4]

M31. (a) A compound made from carbon and hydrogen (not mixture etc.)

1

(b) C5H12

1

(e) (i) Break down

by heat

(ii) Speeds up reaction

(iii) C8H16

each for 1 mark4

[6]

M32. (a) organic1

sediment1

(b) (i) gases1

(ii) bitumen1

(c) (i) cracking

accept thermal decompositiondo not accept endothermic

1

(ii) many or short or small (ethene) moleculesaccept monomeraccept double bonds open up or break

1

join to make larger moleculesaccept polymer accept polymerisationaccept short chain to long chain (or molecules)do not accept unsaturated to saturated

1

(d) poor ventilationaccept limited air supply accept insufficient oxygen

1

causes incomplete combustionaccept produces CO

1

(fumes contain) carbon monoxide which dangeroustoxic is not awarded a markdo not accept harmful or poisonous

1[10]

M33. (a) N2

1

20–21%accept an answer in this range

1

Ar1

(b) (i) compound of carbon and hydrogen onlydo not accept ‘mixture’

1

(ii) Oxygen or O2

1

(iii) exothermicaccept combustion or oxidation

1

(iv) increases greenhouse effect1

global warming or example1

[8]

M34. (a) fractional distillation1

boiling point or use1

(b) (i) mixture: compounds or elements or substances together but not chemically combined

ignore references to separation1

compound: (different) elements or different atoms together and chemically combined

ignore references to separation1

(ii) element: contains only one type of atom

accept made of atoms which contain the same number of protons

1

compound: contains different types of atom chemically combined

‘chemically combined’ not needed here if already stated in (b)(i)

1[6]

M35. (a) (i) heataccept increase temperature ignore pressure

1

with a catalyst1

(ii) 1

accept displayed formulae only1

(iii) O2

1

CO2 + H2Oignore state symbols

1

correct balancing2 + 7 → 4 + 6

accept 1 + 3 → 2 + 3 only if reactants and products correct

1

(b) double bond breaks1

many (ethene) moleculesaccept many monomers

1

bond togetheraccept join or combine for bondaccept

for first 2 marks ignore unsaturated becomes saturated

1[10]

M36. (a) catalyst1

(b) (i) made up of only carbon and hydrogen1

(ii) C8H18

1

(c) (i) ethene

1

(ii) polymerisation1

[5]

M37. (a) C3H8

1

(b) (i) increases / gets larger1

(ii) all 5 points plotted correctlydeduct 1 mark for each incorrectly plotted pointbut ignore –90, 30allow error of one square in any direction

2

smooth line graph

1

(iii) boiling point estimate from their graphallow 2 °C

1

(iv) shown clearly on graphallow just one construction line drawn

1

(c) C9H18

1[8]

M38. (a) all three lines correct two marksone or two lines correct one mark

two ticks only

accept diesel oil joined to cars

1

(b) (i) because it has a different boiling pointaccept because of its boiling pointor it has a boiling point of 40 °C

1

(ii) CO2 or carbon dioxide1

H2O or wateraccept steam

1[5]

M39. (a) (i) by heatingpressure is neutral

using a catalyst/pot/ceramic/porcelain/aluminium oxide1

(ii) use bromine water/(alkaline) permanganate

accept bromine1

alkene makes bromine go colourless or lose its colouraccept alkane does not change the red/orange colour of brominenot change colour/goes clear

1

(b) (i) either of these must show bonds at end

1

or

not H on endsallow 3 instead of n not any other number

(ii) poly(ethene) – brackets not essentialaccept polythene

1

(iii) large amount of waste polymer/poly(ethene)/polythene/litteraccept large amount of crude oil or finite resource used

1

it is not biodegradableaccept it does notdecompose/decay/break downit causes pollution/it creates toxicfumes when burnt are neutralnot it is not recyclable

2[8]

M40. (a) hydrocarbon is a compoundnot mixture not substance

1

containing carbon and hydrogenaccept of the elements carbon and hydrogenaccept of carbon and hydrogencontains hydrogen and carbon only (2)

1

(b) (i) any order

carbon dioxideaccept CO2

exact formulae2

water 1accept H2Onot carbon in one box and dioxide in second box (0)ignore any attempt to ‘balance’ the equation

(ii) it is poisonousaccept toxiccan kill youaccept any reasonable descriptionof its effect on red blood cells or onhaemoglobin in terms of reducingoxygen transport

not can explode, harmful,dangerous, flammable

1[5]

M41. (a) hydrogenaccept correct symbols but not H2

1

carbon1

(b) (i) wateraccept H2O

1

(ii) limewater / calcium hydroxideaccept Ca(OH)2

1

(iii) milky / cloudy / chalky / white1

(c) (i) remains almost the same / increases then decreases slightly from1000 to 1800

1

increases / rises after 18001

rapidly (owtte)1

(ii) increased burning of hydrocarbon / (fossil) fuels, etc. orincreased use of fuels

accept deforestationaccept (more) cars / lorries / planes etc.accept power stationsdo not accept just ‘factories’

1[9]

M42. (a) catalyst or speeds up the reaction (owtte)accept lowers activation energy not just helps reaction to take placeignore increased surface area

1

(b) C8H18

allow H18C8

must be upper casedo not accept powers

1

(c) Bbecause it is a gas or because it has small molecules or because they are small

position and reason for markallow it has a lower / very low boiling point than Aignore references to solubilityaccept does not condensedo not accept light molecules or bubbles into Bdo 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 communicationif the written communication makes sense and it is in context then award Q markQ Q

1

large to small molecules or scientific word that implies smaller,

e.g. alkene / ethane / petrolany name or formula of alkane / alkene smaller than decane

1

either advantages of smaller molecules or disadvantages of larger moleculese.g. hydrocarbons with large molecules are limited in their usefulness

or converse for smaller molecules1

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 neededor converse for smaller molecules

smaller molecules are useful as fuels

alkenes / products can be used to make polymers

(f) (fractional) distillationaccept fractionationaccept good descriptiondo not accept just diagram

1[9]

M43. (a) decane has the largest molecules1

methane and butane are gases at 20 °C1

(b) (i) water1

(ii) carbon dioxide1

(c) sulfur dioxide is produced when sulfur burns1

therefore sulfur must be removed from these fuels becausesulfur dioxide causes acid rain

1[6]

M44. (a) poly(tetrafluoroethene) or polytetrafluoroetheneaccept PTFE or Teflon

1

(b) double bond

1

all other atoms and bonds correct including F for fluorine

ignore n in front

or = 1 mark

= 1 mark

CF2 = CF2 = 1 markdo not accept structures with more than 2 C atoms

1

(c) any three from:

• many monomers / (small) molecules / tetrafluoroethene molecules

allow many tetrafluoroethenesmany particles alone is insufficientdo not accept many polymers

• (monomers, molecules etc.) join / bond / link / combine / attach

allow many particles joinallow many atoms join do not accept collide / add ignore polymerisedo not accept many polymers join

• to form one molecule orto form a long-chain orto form a large molecule

• no other substances are produced /one substance formed (definition of addition)

• idea of double bond breaking / opening / opens / bond beingused to join to another molecule or the double bond becomes a single bond

3[6]

M45. (a) not broken down by microorganisms or not bio-degradableaccept alternative answers such as:do not rot / corrode / fade / react with atmosphere etcany answers which imply the inertness or non-biodegradability of this plasticaccept they don’t react, they are ‘inert’ignore rustingdo not accept weathering

1

(b) (i) (have a) double bond or do not have maximum number of

(hydrogen) atoms attachedaccept can add / react with hydrogenaccept can take part addition reactionsdo not accept it is a double bonddo not accept additional reactionsdo not accept has ‘spare’ / ‘free’ bonddo not accept alkene alone

1

(ii) single bond between carbon atoms1

all atoms correct + 2 ‘linking’ bonds(linking bonds need not go through bracket)

1

n moved to bottom right of bracket i.e. is below way on the right

first 2 marks are possible for chain structuresaccept [– CHCl–CH2–] n

1

(iii) many molecules or many monomers1

joined / bonded / linked or form longchain molecules / large molecules or toform a long chain polymer

accept many alkenes or many (ethene) moleculesdo not accept many ethene alone etc.to form a long polymer is not enough for 2nd mark

1

(iv) no other substances formed(A + B → C)

allow because double bond breaks so other

atoms can addallow one product onlydo not accept saturation occurs

1[8]

M46. (a) any one from:

• gasoline / petrol / it contains short(er) chains / hydrocarbonsor small(er) molecules or contains few(er) carbons

accept fuel oil contains long(er) chain length / large(r) molecules or contains many carbonsignore particles

• gasoline / petrol / it has weak(er) / small(er) intermolecular forces

accept fuel oil has strong(er) / great(er) intermolecular forces

1

(b) only accept figures if used in a comparative statement

any two from:

• gasoline / petrol / it is in high demandaccept fuel oil is in low demand

• gasoline / petrol / it is in short supplyaccept fuel oil is plentifulaccept answers such as ‘gasoline / petrol / its supply is less than demand for 2 marksor gasoline / petrol / its percentage in crude oil is less than demand for 2 marks

• (high) tax / duty

• cracking costs in terms of money / energyaccept cracking expensive

2

(c) any two from:ignore particles

• (fuel oil / it) heated / vaporised

• with catalystaccept a named catalystif first two bullet points are not awarded ‘cracking’ gains 1 mark

• (to give / form / produce) short(er) chains / hydrocarbons or small(er)molecules or contains few(er) carbons

if wrong process named max 1 mark2

[5]

M47. (a) (i) poly(ethene)accept polythene

1

(ii) cracking1

(iii) hydrogen1

(b) (i) bar labelled 91

bar drawn to correct height_1

(ii) (boiling point) increases1

(iii) heat / evaporate (the crude oil)accept separate by boiling point

1

cool / condense (hydrocarbons at different temperatures)accept smaller molecules go to top / larger molecules stay at bottomaccept fractional distillation for two marks or distillation / fractionation for one mark

1

(c) yes

any two from:

• because plastic does not biodegrade or running out of space for landfills orland cannot be used for a long time

• it provides heat energy

• which can be used to generate electricity / heat homes or greenhouses

• any other advantage of burning

• any other disadvantage of landfill

or

no

• burning plastic produces carbon dioxide / carbon emissions / toxic gases

accept landfill does not producecarbon dioxide / carbon emissions

• causes global warming / climate change / increase greenhouse effect / global dimming / acid rain

• any other disadvantage of burning

• any other advantage of landfill2

[10]

M48. (a) alkanes1

catalyst1

substances must be in the order shown

(b) many (ethenes/monomers)1

bond/join together1

allow ethenes / monomers bond / join together to form very large molecules for 2 marks

(c) Marks awarded for this answer will be determined by theQuality of Written Communication (QWC) as well as thestandard of the scientific response.

No relevant content.0 marks

There is a brief description of a positive and a negativeenvironmental impact involved with one or more methodsused to reduce the amount of plastic bags sent to landfill.

Level 1 (1–2 marks)

There is some description of both positive and negativeenvironmental impacts involved with at least 2 methodsused to reduce the amount of plastic bags sent to landfill.


There is a clear, balanced and detailed description of botha positive and a negative environmental impact of usingeach of the 3 methods used to reduce the amount of plasticbags sent to landfill.


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:


• used to make new plastic bags / objects


• saves energy compared to producing plastic bagsfrom crude oil

• cuts down on CO2 emissions

• less global warming


• collection point sites cause an eyesore / litter problem

• transportation to recycling plant releases carbondioxide / causes global warming

burn:bags can be burned so:


• could provide energy for heating buildings

• could provide energy for generating electricity


• increases CO2 emissions

• increases global warming

• could release toxic gases

does not conserve raw materials / crude oil[10]

M49. (a) hydrocarbons1

(b) evaporation1

condensation1

distillationallow fractional distillation

1

(c) lower and more1

[5]

M50. (a) (i) by (fractional) distillationaccept a description of the distillation process (heat and how separation works) eg heat and condenseaccept boil / vapourise etc for heat

or

fractionation1

(ii) CO2

note the order of these products must be correct

1

H2O wrong way round = 1 mark

1

(b) (i) (hexane) has been broken down (into smaller hydrocarbons / molecules)

1

accept (thermal) decomposition / cracked / split / broken up owtte

(ii) H H │ │ C = C │ │ H H

accept CH2 = CH2

1

(iii) water / hydrogen oxide / steamaccept H2O

1

(c) candidates must include both sugar cane and crude oil in their evaluationand 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 oilnot ‘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

• country has oil refineries / cracking plants

• very pure product

• faster process4

[10]

M51. (a) any two environmental problems with linked explanations

• global warming (1)accept effects of global warming

caused by (formation of) carbon dioxide / greenhouse gas (1)ignore greenhouse effect

• acid rain (1)accept effects of acid rainignore respiratory problems

caused by ( formation of) sulfur dioxide (1)accept sulfur oxideignore sulfuric acid

• global dimming (1)ignore respiratory problems

caused by ( formation of) particles / particulates / fires /smoke / carbon / pm 10 (1)

• scarring of landscape (1)

caused by mining / quarrying of coal (1)ignore ozone layer

max 4

(b) any three from:

• replant the trees / renewable / sustainableignore reusable

• carbon dioxide is used by the trees / photosynthesisaccept trees absorb carbon dioxide as they growdo not allow respiration

• it’s a (continuous carbon) cycleaccept ‘carbon dioxide goes back into the air’accept trees use CO2 which is released when trees are burnt

• no ‘new’ carbon (dioxide) is produced orno locked up carbon (dioxide) is released

accept no carbon (dioxide) from fossil fuels is produced

3[7]

M52. (a) (i) hydrogenmust be name

1

(ii) a line of four or more ethene molecules joined to the original twowith single bonds

at least two other ethene molecules joined to the original two in a chain gains 1 mark

2

(b) (i) any two from:

• non-biodegradableaccept remains a long time

• landfill sites are filling up / limitedaccept land / space used up

• waste of a resource / could be recycled / reusedignore references to tablets / animals

2

(ii) any one from:

• (two) different polymers / plastics / materials

• need to be separated

• limited collection points / many need to be collected

• tablets may still be present1

[6]

M53. (a) hydrogenignore formulae

1

(b) any two from:

• different sized molecules / more or less (carbon) atoms (in molecules)

ignore different densities

• fuels have different boiling points

• fuels condense at different temperatures2

(c)

all three correct = 3 markstwo correct = 2 marksone correct = 1 mark

3[6]


1

(ii) cracking1

(iii) hydrogen1




(iii) heat / evaporate (the crude oil)

accept separate by boiling point1


1

(c) yes

any two from:






or

no






[10]

M55. (a) (i) heat / evaporate the crude oil / change to gas or vapour

do not accept heat with catalyst1

cool / condense (hydrocarbons)allow small molecules at top and / or large molecules at bottom

1

at different temperatures / boiling pointsif the answer describes cracking ‘ no marks

1

(ii) C4H10

1

(b) H H H │ │ │ H ─C ─ C ─ C ─ H │ │ │ H H H

1

(c) (i) C5 to C8 fraction are fuels or easier to burn or petrol (fraction)accept C21 to C24 fraction not useful as fuelsdo not accept produce more energy

1

(ii) C2H4

do not accept C4H8

1

(iii) any three from:

• use different / lighter crude oils

• develop markets for low demand fractions

• develop new techniques / equipment to use low demand fractionsas fuels

• cracking

• convert low demand fractions to high demand fractions or biggermolecules to smaller molecules

• develop alternative / bio fuelsdo not accept price

3

[10]

M56. (a) (i) sulfur dioxide / SO2

1

(ii) global dimming1

(iii) carbon dioxide / CO2

ignore ozone1

increases the levels (of carbon dioxide)accept it is a greenhouse gas or causes global warming / greenhouse effect

1

(b) gas / oil bar correct length1

coal bar correct length1

[6]

M57. (a) any two from:

• naphtha has a different / low(er) boiling pointaccept different volatility

• condenses at a different temperature / height_ / place in the column / when it reaches it’s boiling point

• different size of molecules2

(b) (i) C10H22 → C6H14 + 2C2H4

allow multiples1

(ii) (hydrocarbon) heated / vapours1

(passed over a) catalyst / alumina / porous potignore other catalysts

1

(iii) it / ethene is unsaturated or decane and hexane / they are saturated

accept decane and hexane are alkanes / CnH2n+2

or ethene is an alkene / CnH2n

or different homologous series / general formula

1

ethene has a double (carbon carbon) bond or decane and hexane have onlysingle (carbon carbon) bonds

accept ethene has a reactive double (carbon carbon) bond for 2 marks

1

(c) all bonds drawn correctly

1

(d) economic argument against recycling

any one from:

• poly(ethene) / plastic must be collected / transported / sorted / washed

• this uses (fossil) fuels which are expensive1

environmental argument against recycling

any one from:

• uses (fossil) fuels that are non-renewable / formCO2 / CO / SO2 / NOx / particulates

ignore pollution / harmful gases / etc

• washing uses / pollutes water1

counter arguments

any two from:

• collect / transport alongside other waste

• use biofuels (instead of fossil)

• landfill is running out

• landfill destroys habitats

• incinerators are expensive to build


• saves energy needed to make new plastic

• incinerators may produce harmful substances

• incinerator ash goes to landfill

• poly(ethene) is non-biodegradable

• poly(ethene) can be made into other useful items

• more jobs / employment for people2

[12]

M58. (a) (i) thermal decomposition1

(ii) hydration1

(iii) add bromine (water)/iodine solution (to K and L)1

K will decolourise these solutionsorL will not decolourise these solutions

1

(b) (i) 352 (g)for correct answerif answer is incorrect 400 + 114 – 162 gains 1 mark

2

(ii) because 2 molecules of hydrocarbon J had 25molecules of oxygen added

or

because 2 molecules of hydrocarbon J produced 16molecules of carbon dioxide

allow because oxygen has been added to hydrocarbon J for 1 mark

2

(c) (i) raw materials are renewableaccept does not use crude oil

1

(ii) alcohol does not need to be distilledaccept alcohol produced is pure

1

process is continuous1

[11]


1

(ii) cracking1

(iii) hydrogen1




(iii) heat / evaporate (the crude oil)accept separate by boiling point

1


1

(c) yes

any two from:






or

no






[10]

M60. (a) (i) polyethene / poly(ethene)accept polythene / polyethylene

1

(ii) needs heat / energy / high temperature / fuel (for cracking)ignore other processes

1

produces carbon dioxide / CO2

ignore use of CO2 or ‘produces carbon’1

(b) any three from:

• use water from local sources or water from close to home

• recycle bottles in the UK / close to homeaccept do not recycle in other countries / Asia

• (reduction in distance travelled) would reduce CO2 emitted by transport

accept use of transport with low / no carbon

dioxide emissions

• use tap water

• use glass bottles / waxed cartons / metal bottlesdo not accept ‘do not use plastic bottles’ without an alternative material

• do not put in landfill or recycle more

• reuse / refill plastic bottles

• tax imported water / plastic bottles (to offset carbon cost)

• make more / all plastic bottles in UKanswers must be about the reduction of carbon cost

3[6]

M61. (a) (i) acid rainaccept consequences of acid rainallow asthma / bronchitisignore toxic gas

1

(ii) global dimmingaccept 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 neutral3

(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’tabsorb CO2 / absorbed it millions of years ago

1[8]

M62. (a) (i) monomers1

(ii) crude oil1

(b) any three from:

• metal may not corrode away / remains

• plastic remains / does not break down (decay) / not affected by microorganisms

accept non-biodegradable

• should recycle / conserve resources / mend the kettle / burn (plastic) as a fuel

accept it is a waste of materials / resources

• landfill sites are limited / filling up

• water pollutionignore harms wildlife / habitats or problems caused by burning the kettle

3[5]

M63. (a) (i) the greater the number (of carbon atoms), the higher its boiling point

do not accept hydrocarbons for carbon atomsallow converseallow melting point

1

(ii) accept answers in the range 344 to 3501

(iii) 2161

(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 demand1

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 petrolaccept crack diesel or description of cracking

• make diesel cheap(er) (than petrol)or make petrol more expensiveaccept lobby the government to reduce the taxon diesel / increase tax on petrol

• mix ethanol with petrolignore biodiesel

1[6]

M64. (a) (i) many ethene / molecules / monomersaccept double bonds open / break

1

join to form a long hydrocarbon / chain / large moleculeaccept addition polymerisationignore references to ethanecorrect equation gains 2 marks

1

(ii) (can be deformed but) return to their original shape (whenheated or cooled)

ignore ‘it remembers its shape’1

(iii) cross links / extra bonds in PEXaccept inter-molecular bondsignore inter-molecular forces

1

molecules / chains in PEX are held in positionaccept rigid structure

1

molecules / chains in PEX unable to slide past each other /

moveit = PEX throughout

1

(b) any four from:

• less (hydrocarbon) fuels usedallow less energy

• less / no electrical energy usedallow no electrolysis

• reduce carbon / carbon dioxide emissionsallow less global warming

• reduce / no pollution by sulfur dioxide / acid rain

• continuous processallow less / no transportation

• conserve copper which is running out or only low-grade ores available

• reduce the amount of solid waste rock that needs to be disposed

allow less waste

• reduce the need to dig large holes (to extract copper ores)allow less miningignore costs / sustainability / non-renewable

4[10]

M65. (a) (i) C2H4

1

(ii) poly(ethene)1

(b) (i) is not biodegradable1

(ii) not enough landfill sites / spaceaccept landfill sites are filling up or plastics remain for years or plastics not broken downignore cost / waste of resources / not biodegradable / wildlife

1

(iii) less (crude) oil / fuels / energy usedaccept (crude) oil is a non-renewable resource

1

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