In the reaction:

${\mathrm{CS}}_2\left(\mathrm{l}\right)+3{\mathrm{O}}_2\left(\mathrm{g}\right)⟶{\mathrm{CO}}_2\left(\mathrm{g}\right)+2{\mathrm{SO}}_2\left(\mathrm{g}\right)$

$\mathrm{\Delta H}=-265 \mathrm{kcal}$

The enthalpies of formation of ${\mathrm{CO}}_2$ and ${\mathrm{SO}}_2$ are both negative and are in the ratio 4 : 3. The enthalpy of formation of ${\mathrm{CS}}_2$ is +26 kcal/mol. Calculate the enthalpy of formation of ${\mathrm{SO}}_2$ :