Can someone describe the role of water in dissolving Potassium Iodide?

Question

I have searched the whole web for help. I am studying ionic compounds. Any help is appreciated.

Answer 1

The effect is called solvation. Recall that water has a dipole, with a partial positive on hydrogen and a partial negative on oxygen. The oxygen orietates itself to surround the cation (potassium) and the hydrogens align themselves to surround the anion (iodide).

This lowers the energy of the system because the charges are stabilized by the polar solvent. You can see this effect if you try to dissolve KI in hexane .... hexane can't solvate the ions and so it's insoluble.

Answer 2

potassium iodide is an ionic solid. it dissociates in water to its ionic constituents, K+ and I-. it is able to do this because water is a polar solvent and is able to stabilize the ions.