A $5 \mathrm{g}$ sample of impure magnesium carbonate is reacted with an excess of hydrochloric acid:

${\mathrm{MgCO}}_3 \left(\mathrm{s}\right)+2\mathrm{HCl} \left(\mathrm{aq}\right)\to {\mathrm{MgCI}}_2 \left(\mathrm{aq}\right) + {\mathrm{H}}_2\mathrm{O} \left(\mathrm{l}\right) + {\mathrm{CO}}_2 \left(\mathrm{g}\right)$

$1250 {\mathrm{cm}}^3$ of carbon dioxide is collected at rtp. What mass of pure magnesium carbonate would give this volume of carbon dioxide? $\left[{\mathrm{A}}_{\mathrm{r}}: \mathrm{C}=12, \mathrm{O}=16, \mathrm{Mg}=24\right]$