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Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7 Electrolysis.

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Presentation on theme: "Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7 Electrolysis."— Presentation transcript:

1 Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7 Electrolysis

2 Using Exam pro items to support successful outcomes Version 2.0 Copyright © AQA and its licensors. All rights reserved. Learners will be able to test their progress against learning outcomes using questions from past AQA GCSE examinations C2 2.7

3 Foundation Tier- June 12, 4 Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7

4 Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7

5 Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7

6 Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7

7 Mark scheme- Foundation Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7 QAnswerExtra InformationMark (a)(i) Cryolite 1 (a)(ii) Lower the melting point of the aluminium oxide 1 (b)(i) Opposite charges or oxide ions are negative Attract 1111 (b)(ii) Carbon 1 (b)(iii) Reacts with oxygen or forms carbon dioxideAccept burns 1 (c) Structure mark: Either Al (atoms) in layers/rows Or alloy (atoms) not in layers / rows Sliding mark: either so (Al layers) can slide Or so (alloy) layers cannot slide Accept Al (atoms) all the same size Allow Al (atoms) in lines Accept different sizes of atoms in alloy Allow alloy (atoms) not in lines 1111 Total 8

8 Higher Tier June 12, 5 Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7

9 Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7

10 Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7

11 Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7

12 Mark scheme- Higher Version 2.0 Copyright © AQA and its licensors. All rights reserved. C2 2.7 QAnswerExtra InformationMark (a) 52.9 (411765/53 ) Correct answer with or without working = 2 marks If answer is incorrect Allow 2 x 27 = 54 or 27/102 x 100 Or 26.5 for 1 mark 2 (b)(i)Because it lowers the melting point ( of the aluminium oxide) So less energy is needed ( to melt it) Allow lowers the temperature needed. Do not accept lowers boiling point Accept so that the cell / equipment does not melt. 1111 (b)(ii)2 O 2- on left hand side 4e- on right hand side Accept correct multiples or fractions Accept - 4e- on left hand side 1111 (b)(iii)Because the electrode reacts with oxygen or Because the electrode burns To form carbon dioxide or electrode made from carbon / graphite 1111 8

13 C2 2.7


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