Question

The reactions occurring at each electrode are:

Beaker A: Br²(ℓ) + 2e⁻ → 2Br⁻(aq)

Beaker B: SO₃²⁻ (aq) + H₂O(ℓ) → SO₄²⁻ (aq) + 2H⁺ (aq) + 2e⁻

Which of the following equations is the overall redox reaction in the cell?

1. Br₂(ℓ) + SO₃²⁻ (aq) + H₂O(ℓ) + 2e⁻ → 2Br⁻ (aq) + SO₄²⁻ (aq) + 2H⁺ (aq) + 2e⁻
2. 2Br⁻ (aq) + SO₄²⁻ (aq) + 2H⁺ (aq) → Br₂(ℓ) + SO₃²⁻ (aq) + H₂O(ℓ)
3. Br₂(ℓ) + SO₃²⁻ (aq) + H₂O(ℓ) → 2Br⁻ (aq) + SO₄²⁻ (aq) + 2H⁺ (aq)
4. 2Br⁻ (aq) + SO₄²⁻ (aq) → Br₂(ℓ) + SO₃²⁻ (aq)

You may wish to use the data booklet to help you.

1 mark