Cambridge Assessment International Education Cambridge Ordinary Level

Cambridge Assessment International Education Cambridge Ordinary Level

CHEMISTRY Paper 2 Theory MARK SCHEME Maximum Mark: 75

5070/22 October/November 2017

Published

This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners' meeting before marking began, which would have considered the acceptability of alternative answers.

Mark schemes should be read in conjunction with the question paper and the Principal Examiner Report for Teachers.

Cambridge International will not enter into discussions about these mark schemes.

Cambridge International is publishing the mark schemes for the October/November 2017 series for most Cambridge IGCSE?, Cambridge International A and AS Level components and some Cambridge O Level components.

? UCLES 2017

? IGCSE is a registered trademark.

This document consists of 8 printed pages.

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5070/22

Question

A1(a)(i) Iron/Fe (1)

A1(a)(ii) Oxygen/O2 (1)

A1(a)(iii) A1(a)(iv) A1(a)(v)

Hydrogen/H2 (1) Aluminium/Al (1) Aluminium/Al (1)

A1(b)

41K electrons 19 (1) neutrons 22 (1) 17O2? electrons 10 (1) neutrons 9 (1)

Cambridge O Level ? Mark Scheme PUBLISHED

Answer

October/November 2017

Marks 1 1 1 1 1 4

Question

Answer

A2(a) Arrangement: ordered/lattice/regular/layers/uniformly arranged/repeated pattern (1)

Type of force: electrostatic (1)

A2(b) Crystals: ions cannot move (1)

Aqueous: ions can move (1)

A2(c)

Magnesium ion 2,8 (1) Chloride ion 2,8,8 (1)

A2(d)(i)

A2(d)(ii) A2(d)(iii)

Hydrogen is lower in the reactivity series (than sodium) / sodium more reactive (than hydrogen)/hydrogen ions are reduced more easily (than sodium ions) (1)

2H+ + 2e? H2 (1)

Litmus paper/named indicator paper (1)

Bleaches/loses its colour (1)

Marks 2

2

2 1 1 2

? UCLES 2017

Page 2 of 8

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Question A2(e)(i) All four of: H+, OH?, Cl?, Na+ (1)

Cambridge O Level ? Mark Scheme PUBLISHED

Answer

A2(e)(ii) Hydrogen ions removed (1)

Idea of OH? remaining (causing alkalinity) (1)

Question

A3(a)

1 mark each for any two of: ? Shiny/lustrous ? Ductile ? Malleable

A3(b) Iron ................
................

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