What happens when ionic hydrides of $s$-block elements in molten state are electrolysed?

Saline hydrides are known to react with water violently producing fire. Can $CO_2$,a well-known fire extinguisher,be used in this case? Explain.

When steam is passed over red hot iron,the substances formed are

Carbongene has $X\%$ of $CO_2$ and is used as an antidote for poisoning of $Y.$ Then,$X$ and $Y$ are

Complete the following reactions:
$(i) \, H_{2(g)} + M_m O_{o(s)} \xrightarrow{\Delta }$
$(ii) \, CO_{(g)} + H_{2(g)} \xrightarrow[catalyst]{\Delta }$
$(iii) \, C_3 H_{8(g)} + 3 H_2 O_{(g)} \xrightarrow[catalyst]{\Delta }$
$(iv) \, Zn_{(s)} + NaOH_{(aq)} \xrightarrow{heat}$

Oxidation state of hydrogen in compound $X$ is $-1$ and in compound $Y$ is $+1$. $X$ and $Y$ are respectively