Acidified potassium dichromate oxidizes sulphides ($S^{2-}$) to............

sulphur (S)

The correct answer is Option (3) → sulphur (S)

• Acidified potassium dichromate ($K_2Cr_2O_7/H^+$) is a strong oxidizing agent.
• When it reacts with sulfide ions (S²⁻), it oxidizes them to elemental sulfur:

• Further oxidation to $SO_2$​ or $SO_4^{2-}$​ requires stronger conditions.

Hence, the product is Sulfur (S).