Physical Chemistry 1: Redox Multiple Choice Questions

1. Which of the following equations show H₂O₂ acting as a reducing agent?

2Co²⁺ + H₂O₂ → 2Co³⁺ + 2OH^-

5H₂O₂ + 2MnO₄^- + 6H⁺ → 8H₂O + 2Mn²⁺

H₂O₂ + 2NaOH → Na₂O₂ + H₂O

PbS + 4H₂O → PbSO₄ + 4H₂

Correct! Wrong!

2. What is the simplest ionic equation for the reaction of Na₂CO₃ with HNO₃?

Na₂CO₃(aq) + 2HNO₃(aq) → 2NaNO₃(aq) + CO₂(g) + H₂O(I)

Na₂CO₃(aq) + 2H⁺ (aq) → 2Na⁺(aq) + CO₂(g) + CO₂(g) + H₂O(I)

CO₃^2- (aq) + 2H⁺ (aq) → CO₂(g) + H₂O(I)

CO₃^2- (aq) + 2HNO₃(aq) → CO₂(g) + H₂O(I) + NO₃^-(aq)

Correct! Wrong!

3. What is the oxidation number of Chromium in Cr₂O₇^2-?

+6

+7

+12

+14

Correct! Wrong!

4. Which of the following statements is correct?

A reducing agent is an electron pair donor and an oxidising agent is an electron pair acceptor

A reducing agent is an electron pair acceptor and an oxidising agent is an electron pair donor

A reducing agent is an electron acceptor and an oxidising agent is an electron donor

A reducing agent is an electron donor and an oxidising agent is an electron acceptor

Correct! Wrong!

5. Which oxide of nitrogen has the highest oxidation number?

NO₂^-

NO₂

N₂O₅

NO

Correct! Wrong!

6. The equations below show redox reactions of Vanadium species.

Which of the equations is NOT a correctly balanced redox equation?

Zn + 2VO²⁺ + 4H⁺ → 2V³⁺ + 2H₂O + Zn²⁺

3V³⁺ + 3H₂O + NO₃^- + 4H⁺ → 6H⁺ + 3VO²⁺ + NO + 2H₂O

Zn + VO₂⁺ + 2H⁺ → VO²⁺ + H₂O + Zn²⁺

3V²⁺ + NO₃^- + 4H⁺ → 3V³⁺ + NO + 2H₂O

Correct! Wrong!

7. Which of the following rules for finding the oxidation state of an element is correct?

Group 3 elements always have an oxidation state of +3

Hydrogen has an oxidation state of +1 in group 1 metal hydrides

The oxidation number of Chlorine is always negative, unless it’s bonded to Oxygen or Fluorine

The oxidation number of Oxygen is always -2 except in F2O, when the oxidation number is -1

Correct! Wrong!

8. Which of the following reactions is NOT a disproportionation reaction?

2H₂O₂ → 2H₂O + O₂

Ca₃(PO₄)₂ + 2H₂SO₄ → 2CaSO₄ + Ca(H₂PO₄)₂

3ClO^- → 2Cl^- + ClO₃^-

Correct! Wrong!

9. When Chloride reacts as a reducing agent it is oxidised to Chlorine:

2Cl^- → Cl₂ + 2e^-

0.362 moles of Chloride were required to completely reduce 0.181 moles of Lead Oxide (PbO₂).

What is the oxidation number of Lead at the end of this reaction?

+1

-1

+2

-2

Correct! Wrong!

10. In which of the following ions is Iodine present in the +5 oxidation state?

IO₃^-

I^-

I₃^-

IO^-

Correct! Wrong!

Gemma Shearer