Sodium forms a crystalline ionic solid with dihydrogen. The solid is non-volatile and non-conducting in nature. It reacts violently with water to produce dihydrogen gas. Write the formula of this compound and its reaction with water. What will happen on electrolysis of the melt of this solid?

(N/A) Sodium reacts with dihydrogen to form sodium hydride $(NaH)$,which is a crystalline ionic solid.
$2 Na(s) + H_{2}(g) \rightarrow 2 NaH(s)$
It reacts violently with water to produce dihydrogen gas:
$NaH(s) + H_{2}O(l) \rightarrow NaOH(aq) + H_{2}(g)$
Although $NaH$ does not conduct electricity in the solid state,the electrolysis of its melt produces $H_{2}$ gas at the anode and $Na$ metal at the cathode:
$2 NaH(l) \xrightarrow{\text{Electrolysis}} 2 Na(l) + H_{2}(g)$
At cathode: $Na^{+} + e^{-} \rightarrow Na$
At anode: $2 H^{-} \rightarrow H_{2} + 2 e^{-}$