$\mathrm{If} \mathrm{S}+{\mathrm{O}}_2\to {\mathrm{SO}}_2;∆\mathrm{H}=-398.2\mathrm{kj};{\mathrm{SO}}_2\frac{1}{2}{\mathrm{O}}_2\to {\mathrm{SO}}_3;∆\mathrm{H}=-98.7\mathrm{kj}$

${\mathrm{SO}}_3+{\mathrm{H}}_2\mathrm{O}\to {\mathrm{H}}_2{\mathrm{SO}}_4;∆\mathrm{H}=-130.2\mathrm{kj}; {\mathrm{H}}_2\mathrm{O}; ∆\mathrm{H}=-227.3\mathrm{kj}$

The enthalpy of formation of sulphuric acid at 298 K will be