Question

Acidified potassium permanganate solution is decolourised by.

• A. Bleaching powder
• B. White vitriol
• C. Mohr's salt
• D. Microcosmic salt (5) Laughing gas

Answer 1

Answer: (C)

Mohr's salt

Answer 2

Mohr’s salt.

$2 \mathrm { KMnO } _ { 4 } + 8 \mathrm { H } _ { 2 } \mathrm { SO } _ { 4 } + 10 \mathrm { FeSO } _ { 4 } \rightarrow$ $K_{2}SO_{4} + 2MnSO_{4} + 5Fe_{2}(SO_{4})_{3} + 8H_{2}O$

Mohr’s salt decolourises $KMnO_{4}$ by reducing $Mn^{+ 7}$ ions to $Mn^{+ 2}$ ions.