Equivalent weight of KMnO₄ in basic medium is (mol.wt. of KMnO₄ = 158)

Options

(a) 31.5
(b) 52.67
(c) 79
(d) 158

Correct Answer:

52.67

Explanation:

MnO₄⁻ + 2H₂O + 3e⁻ → MnO₂ + 4OH⁻
Equivalent weight = molecular weight / 3.
The oxidation number changes from +7 to +4. so , Equivalent weight = 158/3 = 52.67.