Problem: The ΔHf˚ of TiI3(s) is –328 kJ/mol and the ΔH˚ for the reaction Ti(s) + 3 I 2(g) → 2 TiI3(s) for the reaction is –839 kJ{ m kJ}. Calculate the ΔH of sublimation of I2(s), which is a solid at 25˚C.

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

FREE Expert Solution
FREE Expert Solution

We are asked to calculate the ΔH of sublimation of I2(s)


 We can use the following equation to solve for ΔH˚rxn:


ΔH°rxn=ΔH°f, prod-ΔH°f, react


Note that we need to multiply each ΔH˚f by the stoichiometric coefficient since ΔH˚f is in kJ/mol. 

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 TiI3(s)



View Complete Written Solution
Problem Details

The ΔHf˚ of TiI3(s) is –328 kJ/mol and the ΔH˚ for the reaction Ti(s) + 3 I 2(g) → 2 TiI3(s) for the reaction is –839 kJ. Calculate the ΔH of sublimation of I2(s), which is a solid at 25˚C.