Q1. Crude oil is used to make useful substances such as alkenes and plastics. Formula ( )

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Tamsin Burns
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1 Q. Crude oil is used to make useful substances such as alkenes and plastics. (a) The alkene shown is ethene. (i) Tick ( ) the correct formula for ethene. Formula ( ) CH 4 C 2 H 4 C 2 H 6 () (ii) Tick ( ) the name of the plastic formed when many ethene molecules join together. Name of plastic ( ) Poly(ethene) Poly(ethanol) Poly(propene) () Read the article about plastics and then answer the questions. THE PROBLEM WITH PLASTIC WASTE The UK produces about 3 million tonnes of plastics from crude oil every year. Most of the litter found on UK beaches is plastic waste. 80% of the plastics produced end up in landfill sites. The UK recycles only 7% of plastic waste. (i) Draw a ring around the correct answer in the box to complete the sentence. Litter that is plastic waste needs to be removed from beaches because it decomposes is flammable is not biodegradable. () Page of

2 (ii) Suggest a problem caused by 80% of the plastics going to landfill sites () (iii) The UK government has set a target to recycle 30% of plastic waste. How are resources saved by recycling more plastics? () (Total 5 marks) Q2. Most plastic bags are made from poly(ethene). Poly(ethene) is a polymer made from ethene. Ethene is made by cracking saturated hydrocarbons from crude oil. (a) Use words from the box to complete the sentences about cracking. alkanes alkenes catalyst fuel gas Cracking involves heating the... to make a vapour. The vapour is either passed over a hot... or mixed with steam and heated to a very high temperature so that thermal decomposition reactions happen. (2) Poly(ethene) molecules are made from ethene molecules by a polymerisation reaction. Describe what happens in a polymerisation reaction. (2) Page 2 of

3 (c) In this question you will be assessed on using good English, organising information clearly and using specialist terms where apropriate. 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. (6) (Total 0 marks) Page 3 of

$Q3. The many hydrocarbons in crude oil are separated into fractions. (a) Some of the larger hydrocarbon molecules can be broken down to produce smaller, more useful hydrocarbon molecules.$

4 Q3. The many hydrocarbons in crude oil are separated into fractions. (a) Some of the larger hydrocarbon molecules can be broken down to produce smaller, more useful hydrocarbon molecules. Hexane and butane are alkanes. Describe the structure of alkanes (3) Ethene is used to make poly(ethene). This process is called polymerisation. Explain what is meant by polymerisation (2) (Total 5 marks) Page 4 of

5 Q4. 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 () (ii) ethene () (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 (3) Ethene may be polymerised to form a polymer. Give the name of the polymer and a use for it. Name... Use... () (Total 7 marks) Page 5 of

6 M. (a) (i) C 2 H 4 (ii) poly(ethene) (i) is not biodegradable (ii) not enough landfill sites / space accept landfill sites are filling up or plastics remain for years or plastics not broken down ignore cost / waste of resources / not biodegradable / wildlife (iii) less (crude) oil / fuels / energy used accept (crude) oil is a non-renewable resource [5] M2. (a) alkanes catalyst substances must be in the order shown many (ethenes/monomers) bond/join together allow ethenes / monomers bond / join together to form very large molecules for 2 marks Page 6 of

7 (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. 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. 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. 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. 0 marks Level ( 2 marks) Level 2 (3 4 marks) 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 CO 2 emissions less global warming negative environmental impact could cause litter could still be sent to landfill Page 7 of

8 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 CO 2 emissions less global warming negative environmental impact 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 CO 2 emissions increases global warming could release toxic gases does not conserve raw materials / crude oil [0] M3. (a) any three from carbon (atom) spine / chain accept idea of backbone of carbon (atoms) surrounded by hydrogen (atoms) accept idea of only bonded to hydrogen (atoms) 3 Page 8 of

9 single (covalent) bonds between carbon atoms accept no double bonds saturated (hydrocarbons) (general formula) C n H 2n+2 many small molecules/ monomers accept many unsaturated molecules or alkenes join together to form a large / long molecule / polymer [5] M4. (a) (i) do not credit CH 3 CH 3 (ii) do not credit C 2 H 4 (iii) burn or react with oxygen or combustion or oxidation accept react with chlorine Page 9 of

10 (iv) bubble each gas through (test tube containing) bromine water accept add bromine (water to gas collected) or burn ethene decolourises it or turns the brown colourless accept ethene burns with smoky flame do not accept makes it go clear ethane does not affect it or leaves it brown accept ethane burns with clear flame note carefully the spelling of ethene and ethane 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 [7] Page 0 of

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hij GCSE Science / Chemistry Higher Tier Unit 1 Chemistry SPECIMEN MARK SCHEME Version 1.0

hij GCSE Science / Chemistry Higher Tier Unit Chemistry SPECIMEN MARK SCHEME Version.0 Copyright 20 AQA and its licensors. All rights reserved. The Assessment and Qualifications Alliance (AQA) is a company