Question

KMnO₄ acts as an oxidising agent in acidic medium. The number of moles of KMnO₄ that will be needed to react one mole of sulphide ions in acidic solution is:

(a) 2/5
(b) 3/5
(c) 4/5
(d) 1/5

Answer 1

(a) 2/5

2 mol of KMnO₄ ≡ 5 mol H₂S
2/5 mol of KMnO₄ ≡ 1 mol of H₂S