Hess's Law and Thermochemical Calculations

2025 1 question

1. The standard heat of formation, in $\text{kcal/mol}$ of $\text{Ba}^{2+}$ is:[Given: standard heat of formation of $\text{SO}_4^{2-}$ ion $(aq) = -216\text{ kcal/mol}$, standard heat of crystallization of $\text{BaSO}_4(s) = -4.5\text{ kcal/mol}$, standard heat of formation of $\text{BaSO}_4(s) = -349\text{ kcal/mol}$]