Chapter 9, Problem 112E

The $\Delta {\text{H}}_{\text{f}}^{\text{o}}$ of TiI₃(s) is -328 kJ/mol_; and the $\Delta {\text{H}}^{\text{o}}$ for the reaction $\text{2 Ti}\left(\text{s}\right){\text{+3I}}_{\text{2}}\text{(g) }\to {\text{2 TiI}}_{\text{3}}\left(\text{s}\right)$ is -839 kJ. Calculate the $\Delta \text{H}$ of sublimation (the state transition from solid to gas) of I₂ (s), which is a solid at 25 °C.