Calculate the relative formula mass for the ionic compound Magnesium oxide, $\mathrm{MgO}$.

Iron reacts with excess Sulphuric acid to give Iron $\left(\mathrm{II}\right)$ sulphate. The equation for the reaction is $\mathrm{Fe}\left(\mathrm{s}\right)+{\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{FeSO}}_4\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)$. $5 \mathrm{g}$ of Iron gives $13.6 \mathrm{g}$ of Iron $\left(\mathrm{II}\right)$ sulphate.

Using excess acid, how much Iron $\left(\mathrm{II}\right)$ sulphate can be obtained from $10 \mathrm{g}$ of Iron.