Oxford Revise AQA GCSE Chemistry | Chapter C8 answers

C8: Reactions of metals

Question

Answers

Extra information

Mark

AO / Specification reference

01.1

zinc and copper chloride solution

1

AO2

4.4.1.2

01.2

hydrogen

1

AO1

4.1.2.5

01.3

less vigorously

1

AO1

4.1.2.5

01.4

lithium chloride

1

AO2

4.4.1.2

01.5

sodium > lithium > zinc > copper

one mark for one correct

two marks for two correct

three marks for all correct

3

AO2

4.4.1.2

02.1

reduced

loses

1

1

AO1

4.4.1.3

02.2

2Fe2O3 + 3C → 4Fe + 3CO2

1

AO2

4.4.1.3

02.3

gold is unreactive

so it is found as elemental in the earth

1

1

AO1

4.4.1.3

03.1

steady bubbling from surface of zinc

or zinc gets smaller

or clear gas is formed

1

AO1

4.4.1.2

03.2

zinc chloride and hydrogen

1

AO2

4.4.1.2

03.3

Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)

one mark for formulae and state symbols of reactants & one mark for formulae and state symbols of reactants or one mark for correct formulae & one mark for state symbols

one mark for balancing

3

AO2

4.4.1.2

4.3.1.1

03.4

oxidised

as it loses electrons/forms positive ions

1

1

AO2

04.1

Mg or Al

does not react with CaCl2, so is below Ca in the reactivity series.

reacts with copper sulfate and zinc chloride, so is above these two metals in the reactivity series.

1

1

1

AO2 × 2

AO3 × 1

4.4.1.2

04.2

X(s) + CuSO4(aq) → Cu(s) + XSO4(aq)

one mark for formulae and state symbols of reactants & one mark for formulae and state symbols of reactants or one mark for correct formulae & one mark for state symbols

one mark for balancing

3

AO2

4.4.1.2

4.3.1.1

04.3

test tube full of aluminium salt solution

add metal X

if no observation, then metal is aluminium

if displacement reaction occurs, metal is magnesium

1

1

1

1

AO2

4.4.1.2

05.1

\(
\begin{array}{l}
{\rm{mass\ of\ lead\ sulfide\ in\ the\ ore\ }} = \frac{{25}}{{100}} \times 240{\rm{\ kg\ }} = 60{\rm{\ kg}}\\
{\rm{mass\ of\ one\ mole\ of\ PbS\ }} = 207 + 32 = 239{\rm{\ g}}\\
{\rm{mass\ of\ Pb\ in\ }}60{\rm{\ kg\ of\ PbS\ }} = \frac{{207}}{{239}} \times 60{\rm{\ kg\ }} = 51.96…\\
= 52{\rm{\ kg}}
\end{array}
\)

1

1

1

1

AO2

4.4.1.3

05.2

2PbS(s) + 3O2(g) → 2PbO(s) + 2SO2(g)

one mark for formulae and state symbols of reactants & one mark for formulae and state symbols of reactants or one mark for correct formulae & one mark for state symbols

one mark for balancing

3

AO2

4.3.1.1

05.3

reduced

because oxygen is lost/electrons are gained

1

1

AO1

4.4.1.3

05.4

lead is below carbon in the reactivity series

but aluminium is above carbon in the reactivity series

1

1

AO1

4.4.1.3

05.5

one from:

  • iron
  • copper

1

AO1

4.4.1.3

06

Level 3: A detailed and coherent comparison is given, demonstrating a sound knowledge and understanding of displacement reactions in Halogens and metals.

5-6

AO1

4.4.1.2

4.1.2.6

Level 2: Correct descriptions of displacements are given for the Halogens and in metals. Some comparisons are made, but not all are clearly articulated.

3-4

Level 1: Some correct points are made about displacement reactions. Few comparisons are made, and these are not clearly articulated.

1-2

No relevant content

0

Indicative content

  • in both the Halogen and metal reactions, a more reactive element displaces a less reactive element from a solution of its salt
  • in both cases, one of the products is the less reactive Halogen or metal
  • in both cases, the more reactive element ends up in a compound
  • in the Halogen reaction, the more reactive Halogen is reduced (its atoms each gain one electron)
  • in the metal reaction, the more reactive metal is oxidised (its atoms lose electrons)
  • in the Halogen reaction, reactivity is based on tendency to form negative ions
  • the closer the outer electron is to the nucleus, the more reactive the Halogen
  • in the metal reaction, reactivity is based on the tendency to form positive ions

07.1

lithium

1

AO2

4.4.1.2

07.2

magnesium oxide

1

AO2

4.4.1.1

07.3

oxidised

magnesium has gained oxygen/lost electrons

1

1

AO1

AO2

4.4.1.1

07.4

magnesium is more reactive then carbon

therefore, carbon cannot displace magnesium from magnesium oxide

1

1

AO1

4.4.1.3

08.1

nickel reacts more vigorously than lead with HCl, so it is above lead in the reactivity series

nickel does not react with water, but iron does, so nickel is below iron in the reactivity series

nickel is between iron and lead in the reactivity series

1

1

1

AO3

4.4.1.2

08.2

add nickel to a solution such as iron chloride

there should be no reaction because nickel is less reactive than iron

add iron to a solution of nickel chloride

there should be a reaction because iron is more reactive than nickel

1

1

1

1

AO1

4.4.1.2

08.3

Ni + Cu2+ → Ni2+ + Cu

copper

one mark for reactants, one mark for products

2

1

AO2

4.4.1.4

09.1

do not mix a metal with a solution containing the same metal

allow suitable examples (e.g. do not mix magnesium with magnesium chloride solution)

1

AO3

4.4.1.2

09.2

copper

of the three metals in the experiment, it is the lowest in the reactivity series

or cannot displace any of the other metals

1

1

AO2

4.4.1.2

09.3

Mg(s) + Cu2+(aq) → Mg2+(aq) + Cu(s)

one mark for formulae and state symbols of reactants & one mark for formulae and state symbols of reactants or one mark for correct formulae & one mark for state symbols

one mark for balancing

3

AO2

4.4.1.4

09.4

before: 2,8,2

after: 2,8

1

1

AO2

4.4.1.7

09.5

reduces (potential harmful) waste after experiment

cheaper, as smaller amounts of metals and solutions are required

easier to observe on a white tile than in a test tube

1

1

1

AO3

10.1

there are no gaps/sticks between the nitrogen and hydrogen atoms

1

AO1

4.2.1.4

10.2

N atom should have 1 shell with 5 dots and 3 crosses. H atoms should have 1 shell with 1 dot and 1 cross each.

H atoms should each be sharing 1 dot and 1 cross.

2

AO1

4.2.1.4

10.3

the molecules do not have an overall electric charge/no charged particles that are free to move

1

AO3

4.2.2.1

10.4

gas

1

AO3

4.2.2.1

10.5

hydrazine has bigger molecules

and the intermolecular forces between bigger molecules are stronger

1

1

AO1

4.2.2.4

11.1

metal atoms lose outer shell/highest energy level electrons in their reactions

as atoms become bigger, their outer electrons are further from the nucleus (or more shielding)

so the electrostatic attraction between the nucleus and outer electrons gets weaker

so less energy is required to remove an electron

1

1

1

1

AO1 × 3

AO2 × 1

4.1.2.5

4.4.1.2

11.2

overall, radius decreases from top to bottom of the reactivity series

this indicates that the conclusion is true

calcium and magnesium do not fit the pattern, with both atoms being bigger than the one/two immediately above them in the reactivity series

this indicates that the conclusion is not entirely correct

overall, the trend identified in the conclusion is correct and the reason is correct

1

1

1

1

1

AO3

12.1

heat in a fume cupboard

avoid handling the lead/wash hands

2

AO2

12.2

lead and carbon dioxide

both products required for the mark

1

1

AO2

4.4.1.2

12.3

carbon dioxide has formed as a gas (and escaped from the evaporating basin)

1

AO1

4.3.1.3

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