NaH and $Ca{H}_2$ react with water to produce hydrogen gas according to the following equation.

$M{H}_n+n{H}_{2}OM(OH{)}_n+n{H}_2$

The molar masses of $Na$ and $Ca$ are, $22\mathrm{.}99$ and $40\mathrm{.}08gmo{l}^{-1},$ respectively. Which produces the most $H_2$ per gram?

NaH

$Ca{H}_2$

Per gram, both produce the same.