Question

how many moles of sodium will react with water to produce 2.0 mol of hydrogen in the following reaction?
2Na(s) + 2H20(1) - 2NaOH(aq) + H2(g)

Answer 1

Answer: 4.0 moles of sodium will react with water to produce 2.0 mol of hydrogen

Explanation:

The balanced chemical equation is:

$2Na(s)+2H_2O(l)\rightarrow 2NaOH(aq)+H_2(g)$  

According to stoichiometry :

1 mole of $H_2$ is produced by = 2 moles of $Na$

Thus 2.0 moles of $H_2$ are produced by =$\frac{2}{1}\times 2.0=4.0moles$  of $Na$

Thus 4.0 moles of sodium will react with water to produce 2.0 mol of hydrogen