On heating pyrolusite with $KOH$ in the presence of air,we get:

$X$ is an oxoanion of the lightest element of group $7$ in the periodic table. The metal is in $+6$ oxidation state in $X$. The color of the potassium salt of $X$ is

Which of the following compounds of $Ti$ $(Z = 22)$ does not exist?

The reagent used for toning in photography is

Which of the following is a highly corrosive salt?

$KMnO_4$ decomposes on heating at $513 \ K$ to form $O_2$ along with