Q10 / 160 · TS EAMCET 2016 · Chemistry

The following reaction occurs in acidic medium $\mathrm{KMnO}_4+8 \mathrm{H}^{+}+5 e^{-} \longrightarrow \mathrm{K}^{+}+\mathrm{Mn}^{2+}+4 \mathrm{H}_2 \mathrm{O}$ What is the equivalent weight of $\mathrm{KMnO}_4$ ? (Molecular weight of $\mathrm{KMnO}_4=158$)

  • A
    79.0
  • Correct answer
    B
    31.6
  • C
    158.0
  • D
    39.5

Solution

In the reaction (in acidic medium), $\mathrm{KMnO}_4+8 \mathrm{H}^{+}+5 \mathrm{e}^{-} \longrightarrow \mathrm{K}^{+}+\mathrm{Mn}^{2+}+4 \mathrm{H}_2 \mathrm{O}$ $\mathrm{KMnO}_4$ acts as an oxidising agent in acidic medium. $\mathrm{KMnO}_4$ gains 5 electrons from reductant. $\therefore$ Equivalent weight of $\mathrm{KMnO}_4=\frac{158}{5}$ $=31.6 \text { (in g/equivalent) }$

Hence, the correct answer is option: 'B'.

Relevant Questions