Thank you for reporting, we will resolve it shortly
Q.
When $ MnO_2 $ is fused with $ KOH $ , a coloured compound is formed, the product and its colour are
AMUAMU 2011The d-and f-Block Elements
Solution:
When blackish coloured compound $MnO_2$ is fused with $KOH$ in presence of air, produces a dark green colored compound potassium manganate.
$\underset{\overset{\text{blackish}}{\text{colour}}}{MnO_2} + 4 KOH + O_2 \xrightarrow{\text{Fuse}} \underset{\overset{\text{potassium mangnate}}{\text{(green coloured)}}}{2K_2MnO_4} + H_2O$