The standard enthalpy of formation of gaseous ${\mathrm{H}}_2\mathrm{O}$ at 298 K is $-242 \mathrm{kJ} {\mathrm{mol}}^{-1}$. Calculate ${\mathrm{\Delta H}}^{\circ }$ at 373 K given the following values of the molar heat capacities at constant pressure. 

Molar heat capacity of ${\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)=33.5 {\mathrm{JK}}^{-1} {\mathrm{mol}}^{-1}$ 

Molar heat capacity of ${\mathrm{H}}_2\left(\mathrm{g}\right)=28.8 {\mathrm{JK}}^{-1} 1{\mathrm{mol}}^{-1}$

Molar heat capacity of ${\mathrm{O}}_2\left(\mathrm{g}\right)=29.4 {\mathrm{JK}}^{-1}{\mathrm{mol}}^{-1}$

{Assume that the heat capacities are independent of temperature.}