Q. Preparation of potassium permanganate from $\text{MnO}_2$ involves two step process in which the 1st step is a reaction with KOH and $\text{KNO}_3$ to produce
A) $\text{K}_3\text{MnO}_4$
B) $\text{K}_4[\text{Mn(OH)}_6]$
C) $\text{KMnO}_4$
D) $\text{K}_2\text{MnO}_4$
Explanation
[Solution by Dr. Abubacker] $2\text{MnO}_2+4\text{KOH}+\text{O}_2\ (\text{or KNO}_3)\to2\text{K}_2\text{MnO}_4+2\text{H}_2\text{O}$. The first step gives potassium manganate, $\text{K}_2\text{MnO}_4$, which is then oxidised/disproportionated to $\text{KMnO}_4$. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.