Answer:
d. n H2(g) = 0.034 mol
Explanation:
               2 - Na - 2
               4 - H - 4
                2 - O - 2
∴ n Na(s) = 0.068 mol
⇒ n H2(g) = ( 0.068 mol Na(s) )( mol H2(g) / 2 mol Na(s) )
⇒ n H2(g) = 0.034 mol