12 questions · 12 marks · ≈ 12 min
Extended tier only
Which row correctly describes oxidation in terms of oxygen, electrons and oxidation state?
| oxygen is | electrons are | oxidation state is | |
|---|---|---|---|
| A | added | added | increased |
| B | added | lost | increased |
| C | lost | added | decreased |
| D | lost | lost | decreased |
Choose your answer
Magnesium reacts with iron(III) oxide in the following reaction.
magnesium + iron(III) oxide → magnesium oxide + iron
Which statement about this reaction is correct?
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Magnesium oxide is reduced
Iron is oxidised
Magnesium is oxidised
Iron(III) oxide is oxidised
When copper is heated in air, its surface turns black.
What is happening to the copper in this reaction?
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Copper undergoes thermal decomposition
Copper is oxidised
Copper burns with a lilac flame
Copper is reduced
Lead(II) oxide undergoes a number of different redox reactions.
In which of the following reactions is lead(II) oxide, PbO, not reduced?
Choose your answer
PbO + Zn → Pb + ZnO
PbO + H2 → Pb + H2O
PbO + C → Pb + CO
2PbO + O2 → 2PbO2
The following equations are all examples of redox reactions.
In which equation is the underlined substance being oxidised?
Choose your answer
CO2 + C → 2CO
FeO + Mg → MgO + Fe
3CO + Fe2O3 → 2Fe + 3CO2
CuCO3 → CuO + CO2
Three reactions are shown below.
NO + O3 → NO2 + O2
2C + O2 → 2CO
2MgO + O2 → 2MgO2
Which row correctly describes the process each reactant molecule undergoes?
| NO | O3 | MgO | |
|---|---|---|---|
| A | oxidised | reduced | oxidised |
| B | oxidised | oxidised | reduced |
| C | reduced | oxidised | oxidised |
| D | reduced | reduced | oxidised |
Choose your answer
What is the oxidation state of Fe in Fe2O3?
Choose your answer
+2
-2
-3
+3
Extended tier only
Which row correctly describes the process of reduction in terms of oxygen, electrons and oxidation state?
| oxygen is | electrons are | oxidation state is | |
|---|---|---|---|
| A | lost | added | unchanged |
| B | added | lost | increased |
| C | lost | added | decreased |
| D | added | lost | unchanged |
Choose your answer
Copper(II) oxide reacts with hydrogen gas.
CuO (s) + H2 (g) → Cu (s) + H2O (l)
Which substance is reduced?
Choose your answer
CuO
H2
Cu
H2O
Aqueous copper(II) sulfate reacts with zinc according to the equation shown.
Zn (s) + CuSO4 (aq) → ZnSO4 (aq) + Cu (s)
Which row correctly identifies the oxidising agent and the reducing agent in this reaction?
| oxidising agent | reducing agent | |
|---|---|---|
| A | CuSO4 | Zn |
| B | Zn | CuSO4 |
| C | Cu | ZnSO4 |
| D | ZnSO4 | Cu |
Choose your answer
A series of redox reactions are shown. What is the oxide that undergoes oxidation?
| 1 | 2CO + 2NO → 2CO2 + N2 |
|---|---|
| 2 | Fe2O3 + 2Al → Al2O3 + 2Fe |
| 3 | 2ZnO + C → 2Zn + CO2 |
| 4 | Fe2O3 + 3CO → 2Fe + 3CO2 |
Choose your answer
CO
C
NO
Fe2O3
Extended tier only
In which reaction is the reactant being reduced?
Choose your answer
Mg → Mg2+ + 2ē
Mg2+ + 2ē → Mg
CrO → Cr2O3
C → CO2