Question

Potassium manganate $\left(K_{2}Mn{O}_4\right)$ is formed when:

• A. $C{l}_2$ is passed into an aqueous $KMn{O}_4$ solution
• B. MnO₂ is fused with KOH in air
• C. Formaldehyde reacts with $KMn{O}_4$ is presence of strong alkali
• D. $KMn{O}_4$ reacts with concentrated $H_{2}S{O}_4$

Answer 1

The correct option is B

MnO₂ is fused with KOH in air

$2Mn{O}_2+4KOH+O_2\to 2K_{2}Mn{O}_4+2H_{2}O$

$2K_{2}Mn{O}_4+C{I}_2\to 2KMn{O}_4+2KCI$