# Calculating Heat of Solution of a Compound comparing to other compound data

For example if I have a table with these data

How can those data be compared with each other to find heat of solution of $$\ce{KI}$$?

• Here is an idea. Replacing $\ce{Na}$ by $\ce{K}$ should be the same in chloride and in iodide. So, in chloride, this change in the heat of solution is accompanied by an increase of $13.2$ kJ/mol. In iodides, the heat of solution of KI maybe obtained by the same change, and this gives $-5.1 + 13.2 = + 8.1$ kJ/mol. I am not sure of the validity of my reasoning, because it does not take into account the lattice energy. I would be happy to know more. Aug 27 at 16:42