Molar gas volume

A student reacts 0.20 mol of magnesium with excess hydrochloric acid. The reaction is

$\text{Mg} + 2\text{HCl} \rightarrow \text{MgCl}_2 + \text{H}_2$.

What is the maximum volume of hydrogen gas produced at room temperature and pressure (RTP), where 1 mol of gas occupies 24 dm³?