Question

When $Mn{O}_2$ is fused with $KOH$ in the presence of air, the product formed is :

• A. purple colour $KMn{O}_4$
• B. green colour $K_{2}Mn{O}_4$
• C. colourless $Mn{O}_4$
• D. purple colour $K_{2}Mn{O}_4$

Answer 1

The correct option is B green colour $K_{2}Mn{O}_4$

When $Mn{O}_2$ fused with $KOH$ in the presence of air, green coloured potassium manganate $K_{2}Mn{O}_4$ is obtained.
Reaction evolved:
$2Mn{O}_2+4KOH+O_2\to 2K_{2}Mn{O}_4+2H_{2}O$