🤓 Based on our data, we think this question is relevant for Professor Robinson & Ye's class at IU.

We are asked to calculate the ΔH of sublimation of I_{2}(s)

We can use the following equation to solve for **ΔH˚ _{rxn}**:

$\overline{){\mathbf{\Delta H}}{{\mathbf{\xb0}}}_{{\mathbf{rxn}}}{\mathbf{=}}{\mathbf{\Delta H}}{{\mathbf{\xb0}}}_{\mathbf{f}\mathbf{,}\mathbf{}\mathbf{prod}}{\mathbf{-}}{\mathbf{\Delta H}}{{\mathbf{\xb0}}}_{\mathbf{f}\mathbf{,}\mathbf{}\mathbf{react}}}$

Note that we need to *multiply each ΔH˚ _{f} by the stoichiometric coefficient* since ΔH˚

Also, note that ΔH˚_{f} for elements in their standard state is 0.

ΔH˚_{f TiI3(s)} = –328 kJ/mol

ΔH˚_{f Ti(s)} = 0 kJ/mol (standard state)

We also need to convert ΔH˚_{rxn} from kJ/mol to J/ mol so our units remain consistent.

Ti(s) + 3 I _{2}(g) → 2 TiI_{3}(s)

The ΔH_{f}˚ of TiI_{3}(s) is –328 kJ/mol and the ΔH˚ for the reaction Ti(s) + 3 I _{2}(g) → 2 TiI_{3}(s) for the reaction is –839 kJ. Calculate the ΔH of sublimation of I_{2}(s), which is a solid at 25˚C.