Intext : What happens when H2S is passed into an acidified potassium dichromate solution? 

Question

What happens when H₂S is passed into an acidified potassium dichromate solution? 

Answer

When H2_S is passed into an acidified potassium dichromate (K₂Cr₂O₇) solution, it is oxidized to sulfuric acid (H₂SO₄) and elemental sulfur (S) is formed.

3H₂S (g) + K₂Cr₂O₇ (aq) + 4H₂SO₄ (aq) → 3S ↓ (s) + Cr₂(SO₄)₃ (aq) + K₂SO₄ (aq) + 7H₂O (l)