Question

Give two reactions in which acidified K₂Cr₂O₇ is used as an oxidizing agent.

Answer 1

Oxidation of I⁻ of Kl to I₂:

K₂Cr₂O₇ + 6KI + 7H₂SO₄ → 4K₂SO₄ + Cr₂(SO₄)₃ + _7H2O + 3I₂

Oxidation of H₂S to S:

K₂Cr₂O₇ + 4H₂SO₄ + 3H₂S → K₂SO₄ + Cr₂(SO₄)₃ + 7H₂O + 3S