An acidified manganate solution undergoes disproportionation reaction. The spin-only magnetic moment value of the product having manganese in higher oxidation state is $....\, B.M.$ (Nearest integer)

The transition metal which forms a green compound in $+3$ oxidation state and a yellow-orange compound in $+6$ oxidation state is

On heating a mixture of common salt and $K_{2}Cr_{2}O_{7}$ with concentrated $H_{2}SO_{4}$,a gas is evolved. The formula of the gas evolved and the oxidation state of the central metal atom in the gas,respectively,are:

$X + KOH + O_2 \to Y + H_2O$,
$Y + H_2SO_4 \to Z + K_2SO_4 + MnO_2 + H_2O$
Identify $X, Y$ and $Z$ in the above reactions.

Which among the following statements is incorrect for interstitial compounds?
$1$. They are very hard and rigid
$2$. They have higher melting point than pure metal
$3$. They do not show conductivity
$4$. They are chemically inert

Given below are two statements:
Statement $I$: Fusion of $MnO_2$ with $KOH$ and an oxidising agent gives dark green $K_2MnO_4$.
Statement $II$: Manganate ion on electrolytic oxidation in alkaline medium gives permanganate ion.
In the light of the above statements,choose the correct answer from the options given below.