I am trying to figure out how an author has determined the heat capacity of a substance from limited information. The authors cite a particular book that contains only the following information:
$H_{298} = -40.8$ kcal
$S_{298} = 47.2$ cal / mol K
$\Delta G_{1773} = 7.480$ kcal / g-atom
where $H_{298}$ is the enthalpy at 298$\,$K, $S$ is the entropy and $\Delta G$ is the Gibbs free energy of the reaction.
The authors then claim/calculate/suppose that, at 298K, the heat capacity at constant pressure, $C_P$ , is 31.19 cal / mol K
I am confused as I believe you need to know how $H$ or $S$ changes as a function of $T$ in order to calculate $C_P$? My apologies if I am missing some easy bit of logic here.