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Specification Points
Year 10 – Organic Chemistry
Crude oil, hydrocarbons and alkanes - know • crude oil is a mixture of a large number of compounds, mainly hydrocarbons ( alkanes) • alkanes are a homologous series with a general formula of CnH2n+2 • the names of the first four members of the alkanes
Fractional distillation and petrochemicals - know • what a fraction is and how fractional distillation is used to separate fractions • that fractions are processed to produce fuels +feedstock for the petrochemical industry. • that fuels on which we depend for our modern lifestyle, such as petrol, diesel oil,
kerosene, heavy fuel oil and liquefied petroleum gases, are produced from crude oil. • that many useful materials on which modern life depends are produced by the
petrochemical industry, such as solvents, lubricants, polymers, detergents.
Properties of hydrocarbons - know • how boiling point, flammability and viscosity of hydrocarbons is affected by the
molecular size of a hydrocarbon molecule which affects its use as a fuel • and write equations for the complete combustion of a hydrocarbon fuel
Cracking and alkenes - know • what cracking is, how it happens and why it is used • how to balance cracking equations and know the products of a cracking reaction • the test for alkenes • Cracking produces small molecules which have high demand for use in fuels and as a
starting material for polymerisation
Structure, formulae and reactions of alkenes - know • what an alkene is and the first 4 members of the homologous series • how to describe and write equations to show an alkene reacting with oxygen hydrogen,
water and the halogens by the addition of atoms across the carbon-carbon double bond
Polymers - know • what a polymer is, its bonding and how it is formed • know that the intermolecular forces between polymer molecules are relatively strong
and so these substances are solids at room temperature.
Addition polymerisation - know • that many small molecules (monomers) join to form large molecules (polymers). • how poly(ethene) and poly(propene) are made by addition polymerisation. • be able to recognise addition polymers and monomers from diagrams in the forms
shown and from the presence of the functional group C=C in the monomers • be able to draw diagrams to show a polymer formed from a given alkene monomer in
addition to identifying the monomer from polymers
Ceramics, polymers and composites - know • how glass is made • how clay ceramics (pottery and bricks) are made. • how low density (LD) and high density (HD) poly(ethene) are produced from ethene
Organic Chemistry
using different catalysts and reaction conditions. • what thermosoftening polymers and thermosetting polymers are and relate their
properties to their structures • what a composite is and be able to give examples • be able to compare quantitatively the physical properties of glass and clay ceramics,
polymers, composites and metals • be able to explain how the properties of materials relate to their uses
Year 11 Organic Chemistry
Alcohols Alcohols contain the functional group –OH. Methanol, ethanol, propanol and butanol are the first four members of a homologous series of alcohols. Alcohols can be represented in the following forms: CH3CH2OH or structural formulae Methanol, ethanol, propanol and butanol: • dissolve in water to form a neutral solution • react with sodium to produce hydrogen • burn in air to produce carbon dioxide and water • are oxidised to produce carboxylic acids • are used as fuels and solvents, and ethanol is the main alcohol in alcoholic drinks. Aqueous solutions of ethanol are produced when sugar solutions are fermented using yeast. Be able to: • recognise alcohols from their names or from given formulae up to butanol • know the conditions used for fermentation of sugar using yeast. • write balanced chemical equations for the reactions of alcohols other than for
combustion reactions.
Carboxylic acids Carboxylic acids have the functional group – COOH. The first four members of a homologous series of carboxylic acids are methanoic acid, ethanoic acid, propanoic acid and butanoic acid. Carboxylic acids: • dissolve in water to produce acidic solutions • react with carbonates to produce carbon dioxide • do not ionise completely when dissolved in water and so are weak acids • react with alcohols in the presence of an acid catalyst to produce esters, for example
ethanoic acid reacts with ethanol to produce ethyl ethanoate and water. Be able to • recognise carboxylic acids from their names or from given formulae up to butanoic acid. • write balanced chemical equations for the reactions of carboxylic acids. • know the name of esters ethyl ethanoate.
Condensation polymerisation • Condensation polymerisation involves monomers with two functional groups. When
these types of monomers react they join together, usually losing small molecules such as water, and so the reactions are called condensation reactions.
• The simplest polymers are produced from two different monomers with two of the same functional groups on each monomer. For example: ethane diol and hexanedioic acid polymerise to produce a polyester:
• Be able to explain the principles of condensation polymerisation in relation to the functional groups in the monomers and the repeating units in the polymers.
Amino acids • Amino acids have two different functional groups in a molecule. Amino acids react by
condensation polymerisation to produce polypeptides. • For example: glycine is H2NCH2COOH and polymerises to produce the polypeptide
(-NCH2COO-)n and nH2O. • Different amino acids can be combined in the same chain to produce proteins.
DNA (deoxyribonucleic acid) and other naturally occurring polymers • DNA (deoxyribonucleic acid) is a large molecule essential for life. DNA encodes genetic
instructions for the development and functioning of living organisms and viruses. • Most DNA molecules are two polymer chains, made from four different monomers
called nucleotides, in the form of a double helix. Other naturally occurring polymers important for life include proteins, starch and cellulose. Proteins are polymers of amino acids. Starch and cellulose are polymers of sugars. Sugars, starch and cellulose are carbohydrates.
Independent Study suggestions
1. Look at the specification points above – use the textbook pages (244-277) to make a few notes/spider diagram/revision cards
2. Watch the Fuse School short 3-4 minute explanation videos on any area you need extra help with:
Coal, oil and gas: https://www.fuseschool.org/topics/59/contents/828
Fractional distillation: https://www.fuseschool.org/topics/59/contents/269
Uses of crude oil fractions: https://www.fuseschool.org/topics/59/contents/830
Functional groups: https://www.fuseschool.org/topics/59/contents/270
Formulae of organic compounds: https://www.fuseschool.org/topics/59/contents/268
Alkanes and Alkenes: https://www.fuseschool.org/topics/59/contents/233
Complete and incomplete combustion: https://www.fuseschool.org/topics/65/contents/330
Isomers: https://www.fuseschool.org/topics/59/contents/1198
Cracking: https://www.fuseschool.org/topics/59/contents/273
Alkenes and bromine water: https://www.fuseschool.org/topics/59/contents/829
Halogenation: https://www.fuseschool.org/topics/59/contents/883
Alcohols: https://www.fuseschool.org/topics/59/contents/288
Making alcohols: https://www.fuseschool.org/topics/59/contents/945
Polymers: https://www.fuseschool.org/topics/59/contents/1000
Themosetting and thermosoftening polymers: https://www.fuseschool.org/topics/59/contents/972
Making polyethene: https://www.fuseschool.org/topics/59/contents/943
Polymers from chloroethene an propene https://www.fuseschool.org/topics/59/contents/279
Condensation polymers: https://www.fuseschool.org/topics/59/contents/267
Synthetic polymers: https://www.fuseschool.org/topics/59/contents/942
Natural polymers: https://www.fuseschool.org/topics/59/contents/276
Proteins: https://www.fuseschool.org/topics/59/contents/408
Carbohydrates: https://www.fuseschool.org/topics/59/contents/884 3. Now have a go at the past paper questions below which you can then mark using the markscheme at
the end.
Q1.This question is about organic compounds.
Hydrocarbons can be cracked to produce smaller molecules.
The equation shows the reaction for a hydrocarbon, C18H38
C18H38 → C6H14 + C4H8 + 2 C3H6 + C2H4
(a) Which product of the reaction shown is an alkane?
Tick one box.
C2H4
C3H6
C4H8
C6H14
(1)
(b) The table below shows the boiling point, flammability and viscosity of C18H38 compared with the other hydrocarbons shown in the equation.
Boiling point Flammability Viscosity
A highest lowest highest
B highest lowest lowest
C lowest highest highest
D lowest highest lowest
Which letter, A, B, C or D, shows how the properties of C18H38 compare with the properties of C2H4, C3H6, C4H8 and C6H14?
Tick one box.
A
B
C
D
(1)
(c) The hydrocarbon C4H8 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 C4H8 + 4O2 → 4CO + 4H2O
C C4H8 + 6O2 → 4CO2 + 4H2O
D C4H8 + 8O → 4CO2 + 4H2
Tick one box.
A
B
C
D
(1)
Q2.This question is about hydrocarbons.
(a) Most of the hydrocarbons in crude oil are alkanes.
(i) Large alkane molecules can be cracked to produce more useful molecules.
The equation shows the cracking of dodecane.
Give two conditions used to crack large alkane molecules.
1 ................................................................................................................
2 ................................................................................................................ (2)
(ii) The products hexene and ethene are alkenes.
Complete the sentence.
When alkenes react with bromine water the colour changes from orange to .................................................. .
(1)
(iii) Butane (C4H10) is an alkane.
Complete the displayed structure of butane.
(1)
(b) A group of students investigated the energy released by the combustion of four hydrocarbon fuels.
The diagram below shows the apparatus used.
Each hydrocarbon fuel was burned for two minutes.
Table 1 shows the students’ results. Table 1
After two minutes
Name and formula of hydrocarbon fuel
Mass of fuel used
in g
Temperature increase of water in °C
Energy released by fuel in
kJ
Energy released
by 1.0 g of fuel in kJ
Relative amount of smoke in the flame
Hexane, C6H14 0.81 40 16.80 20.74 very little smoke
Octane, C8H18 1.10 54 22.68 20.62 some smoke
Decane, C10H22
1.20 58 24.36 smoky
Dodecane, C12H26
1.41 67 28.14 19.96 very smoky
(i) Calculate the energy released by 1.0 g of decane in kJ.
...................................................................................................................
...................................................................................................................
Energy released = ...................................... kJ (2)
(ii) Suggest one improvement to the apparatus, or the use of the apparatus, that would make the temperature increase of the water for each fuel more accurate.
Give a reason why this is an improvement.
...................................................................................................................
...................................................................................................................
................................................................................................................... (2)
(iii) The students noticed that the bottom of the beaker became covered in a black substance when burning these fuels.
Name this black substance.
Suggest why it is produced.
...................................................................................................................
...................................................................................................................
...................................................................................................................
................................................................................................................... (2)
(iv) A student concluded that hexane is the best of the four fuels.
Give two reasons why the results in Table 2 support this conclusion.
1 ................................................................................................................
...................................................................................................................
2 ................................................................................................................
................................................................................................................... (2)
(c) In this question you will be assessed on using good English, organising information clearly and using specialist terms where appropriate.
Most car engines use petrol as a fuel.
• Petrol is produced from the fractional distillation of crude oil.
• Crude oil is a mixture of hydrocarbons.
• Sulfur is an impurity in crude oil.
Car engines could be developed to burn hydrogen as a fuel.
• Hydrogen is produced from natural gas.
• Natural gas is mainly methane.
Table 2 shows information about petrol and hydrogen.
Table 2
Petrol Hydrogen
State of fuel at room
temperature Liquid Gas
Word equation for
combustion of the fuel petrol + oxygen → carbon
dioxide + water
hydrogen + oxygen →
water
Energy released from
combustion of 1 g of the fuel
47 kJ 142 kJ
Describe the advantages and disadvantages of using hydrogen instead of petrol in car engines.
Use the information given and your knowledge and understanding to answer this question. (6)
(Total 18 marks)
Q3.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)
(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
C6H14 14 15 15 15
C7H16 19 20 18
C8H18 27 26 28 27
C10H22 46 48
47
C12H26 65 67 69 67
(i) The student did the experiment three times with each liquid hydrocarbon.
Give two reasons why.
...............................................................................................................
...............................................................................................................
............................................................................................................... (2)
(ii) Use the data in Table 1 to calculate the mean time, in seconds, for C7H16
...............................................................................................................
...............................................................................................................
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.
...............................................................................................................
............................................................................................................... (1)
(v) Suggest one error the student may have made to get the ringed result.
...............................................................................................................
...............................................................................................................
............................................................................................................... (1)
(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.
• 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.
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
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.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
............................................................................................................... (3)
(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.
...............................................................................................................
...............................................................................................................
...............................................................................................................
............................................................................................................... (2)
(Total 22 marks)
Q4. Crude oil is a mixture of mostly alkanes.
(a) Crude oil is separated into useful fractions by fractional distillation.
(i) Describe and explain how the mixture of alkanes is separated by fractional distillation.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
.......................................................................................................................... (3)
(ii) The table gives the name and formula for each of the first three alkanes.
Complete the table to show the formula of butane.
Name of alkane Formula
Methane CH4
Ethane C2H6
Propane C3H8
Butane
(1)
(b) The structural formula of methane, CH4, is:
H │ │ H
Draw the structural formula of propane, C3H8
(1)
(c) The relative amounts of and the market demand for some hydrocarbons from the fractional distillation of crude oil are shown in the graph.
(i) Why is the market demand for the C5 – C8 fraction higher than the market demand for the C21 – C24 fraction?
..........................................................................................................................
.......................................................................................................................... (1)
(ii) Cracking is used to break down large hydrocarbon molecules into smaller hydrocarbon molecules.
Complete the symbol equation by writing in the formula of the other hydrocarbon.
C20H42 C16H34 + 2 .......................................... (1)
(iii) The C5 – C8 fraction has low supply and high market demand.
Suggest three ways in which the oil industry could overcome this problem.
............................................................................................................................
............................................................................................................................
..........................................................................................................................
3 .......................................................................................................................
.......................................................................................................................... (3)
(Total 10 marks)
Q5. To make a plastic, such as poly(ethene), from crude oil involves many processes.
(a) Describe how crude oil is separated into fractions.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................ (2)
(b) Ethene is produced by cracking the hydrocarbons in the naphtha fraction.
(i) Balance the symbol equation for this reaction.
C10H22
decane → C4H10
butane + C2H4
ethene
(1)
(ii) Describe how cracking is carried out.
...............................................................................................................
...............................................................................................................
...............................................................................................................
...............................................................................................................
............................................................................................................... (2)
(c) Alkanes, such as butane (C4H10), do not form polymers.
Alkenes, such as ethene (C2H4), do form polymers.
Explain these statements.
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................
........................................................................................................................ (2)
(d) Ethene molecules form the polymer poly(ethene). One molecule in poly(ethene) will contain thousands of carbon atoms. The diagram represents part of a poly(ethene) molecule.
Propene molecules form the polymer poly(propene).
Draw a diagram to represent part of a poly(propene) molecule.
(2)
(Total 9 marks)
Q6.Ethene is used to produce poly(ethene).
(a) Draw the bonds to complete the displayed formulae of ethene and poly(ethene) in the equation.
(2)
(b) Polyesters are made by a different method of polymerisation.
The equation for the reaction to produce a polyester can be represented as:
Compare the polymerisation reaction used to produce poly(ethene) with the polymerisation reaction used to produce a polyester.
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
.............................................................................................................................
............................................................................................................................. (4)
(Total 6 marks)
Q7.Figure 1 shows how ethanol is made from plants and from crude oil.
(a) What is the name of the reaction to produce ethanol from sugar?
Tick (✔) one box.
fermentation
polymerisation
reduction
(1)
(b) A student made ethanol from sugar.
Figure 2 shows the apparatus used.
(i) What change is seen in the limewater? Give a reason for your answer.
...................................................................................................................
................................................................................................................... (2)
(ii) The student wanted to separate the solid yeast from the solution.
Figure 3 shows the apparatus used.
What is missing from the apparatus in Figure 3?
...................................................................................................................
................................................................................................................... (1)
(Total 4 marks)
Q8.This question is about organic compounds.
(a) Ethanol is an alcohol. One use of ethanol is in alcoholic drinks.
Give two other uses of ethanol.
........................................................................................................................
........................................................................................................................ (2)
(b) Which gas is produced when sodium reacts with ethanol?
Tick ( ) one box.
Carbon dioxide
Carbon monoxide
Hydrogen
Oxygen
(1)
(c) Ethanoic acid (CH3COOH) can be produced from ethanol (CH3CH2OH).
(i) What type of reaction produces ethanoic acid from ethanol?
............................................................................................................... (1)
(ii) Complete the displayed structure of ethanoic acid.
(1)
(iii) Solutions of ethanoic acid and hydrochloric acid with the same concentration have different pH values.
Explain why the solution of ethanoic acid has a higher pH than the solution of hydrochloric acid.
...............................................................................................................
...............................................................................................................
...............................................................................................................
............................................................................................................... (2)
(d) Ethanol and ethanoic acid react in the presence of a catalyst to form an ester.
(i) Name the ester made from ethanol and ethanoic acid.
............................................................................................................... (1)
(ii) What type of chemical is used as a catalyst in this reaction?
............................................................................................................... (1)
(iii) Esters are used in perfumes because they smell pleasant and are volatile.
What does volatile mean?
............................................................................................................... (1)
(Total 10 marks)
Answers:
M1.(a) C6H14
1
(b) A 1
(c) B 1
M2.(a) (i) high temperature
allow heating / hot / 250-900 °C 1
catalyst or steam
allow named catalyst eg zeolite, Al2O3, silica, ceramic
allow in the absence of air / oxygen 1
ignore any references to pressure
(ii) colourless
allow decolourised
ignore clear / discoloured 1
(iii) 1
(b) (i) 20.3(0) (kJ)
if answer incorrect allow 1 mark for 24.36/1.2 2
(ii) use a lid
allow insulate beaker or use draught shield 1
reduce energy / heat loss
ignore references to thermometer or repeats or distance of flame or loss of water
vapour
allow stir (1) to distribute energy / heat (1)
allow use a metal can (1) as it’s a better conductor (1) 1
(iii) carbon/soot
ignore tar, smoke 1
(produced by) incomplete combustion
allow from a limited supply of oxygen/air 1
(iv) hexane gives out the greatest energy (per 1.0 g)
ignore more energy 1
hexane produces the least smoke / carbon / soot
allow has the cleanest flame
ignore less smoke / carbon / soot 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. Examiners should also apply a ‘best-fit’ approach to the marking.
Level 3 (5 – 6 marks): Descriptions of advantages and disadvantages that are linked to their own knowledge.
Level 2 (3 – 4 marks): Descriptions of an advantage and a disadvantage with some use of their knowledge to add value.
Level 1 (1 – 2 marks): Statements made from the information that indicate whether at least one statement is an advantage or a disadvantage or a linked advantage or disadvantage
0 marks: No relevant content
Examples of the added value statements and links made in the response could include: Note that link words are in bold; links can be either way round. Accept reverse arguments and ignore cost throughout.
Advantages of using hydrogen: • Combustion only produces water so causes no pollution • Combustion does not produce carbon dioxide so this does not contribute to global warming or climate change • Combustion does not produce sulfur dioxide so this does not contribute to acid rain • Incomplete combustion of petrol produces carbon monoxide that is toxic • Incomplete combustion of petrol produces particulates that contribute to global dimming • Petrol comes from a non-renewable resource but there are renewable/other methods
of producing hydrogen • Hydrogen releases more energy so less fuel needed or more efficient
Disadvantages of using hydrogen: • Hydrogen is a gas so is difficult to store or transfer to vehicles • Hydrogen gas is very flammable so leaks cause a greater risk of explosion • Most hydrogen is produced from fossil fuels which are running out • Cannot be used in existing car engines so modification / development or replacement is needed • Lack of filling stations so difficult to refuel your vehicle
6
[18]
M3.(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
(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]
M4. (a) (i) heat / evaporate the crude oil / change to gas or vapour
do not accept heat with catalyst 1
cool / condense (hydrocarbons)
allow small molecules at top and / or large molecules at bottom 1
at different temperatures / boiling points
if 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 fuels
do 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 fractions as fuels
• cracking
• convert low demand fractions to high demand fractions or bigger molecules to smaller molecules
• develop alternative / bio fuels
do not accept price 3
[10]
M5. (a) vaporise / evaporate
allow boil for vaporise 1
different condensing points / temperatures
accept condense at different levels
ignore different size molecules or different densities
mention of cracking = max 1
allow boils at different temperatures and condenses for 2 marks
if no other marks awarded allow
fractional distillation for 1 mark 1
(b) (i) 3 (C2H4)
accept +C4H8
1
(ii) (decane / naphtha / hydrocarbon) vaporise / evaporate
allow crude oil
allow boil for vaporise 1
(passed over) a catalyst / alumina / porous pot
ignore other names of catalysts 1
(c) any two from:
‘they’ must be clarified
• alkanes / butane (molecules) do not have a (carbon carbon) double bond / are saturated / have (carbon carbon) single bonds
• alkenes / ethene (molecules) have (carbon carbon) double bonds
or are unsaturated
• alkenes / ethene molecules are able to bond to other molecules 2
(d) single bonds between carbon atoms
– C - C – 1
the -CH3 group appears on each pair of carbons on the ‘chain’
NB any double bonds = 0 marks 1
[9]
M6.(a) (ethene)
1
(polyethene)
1
(b) any four from:
• poly(ethene) produced by addition polymerisation whereas polyester by condensation polymerisation
• poly(ethene) produced from one monomer wheareas polyester produced from two different monomers
• poly(ethene) produced from ethene / alkene whereas polyester from a (di)carboxylic acid and a diol / alcohol
• poly(ethene) is the only product formed whereas polyester water also produced
• poly(ethene) repeating unit is a hydrocarbon whereas polyester has an ester linkage
4
[6]
M7.(a) fermentation 1
(b) (i) turns cloudy / milky / white
ignore bubbles 1
because carbon dioxide is produced
allow CO2 produced 1
(ii) filter paper 1
[4]
M8.(a) any two from:
• fuel
allow source of energy • solvent
allow perfume / aftershave • antiseptic
allow antibacterial 2
(b) Hydrogen 1
(c) (i) oxidation
do not allow redox 1
(ii) correct structure 1
(iii) ethanoic acid is a weak / weaker acid
it = ethanoic acid 1
because it does not completely ionise.
allow because it does not completely dissociate
allow it has a lower concentration of hydrogen ions
allow converse for hydrochloric acid
do not allow ionising 1
(d) (i) ethyl ethanoate 1
(ii) acid
allow any strong acid
allow correct formulae 1
(iii) evaporates easily / quickly
allow low boiling point
do not allow flammable 1
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