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

Which of the following reactions give $H_2$ as one of the products? (Reactions are not balanced)
$I) NaBH_4 + I_2 \longrightarrow$
$II) B_2H_6 + N(CH_3)_3 \longrightarrow$
$III) Al + NaOH + H_2O \longrightarrow$
$IV) BF_3 + NaH \longrightarrow$

Deuterium resembles hydrogen in properties but:

Which of the following is a synthesis gas?

Which is an example of a molecular hydride?

Carbon monoxide is a neutral oxide of carbon,but it acts as a very strong field ligand and associates with metals to form complex compounds. These complex compounds are very useful and used in metallurgical processes. Water gas is a mixture of