Use le chatelier's principle to explain why the solubility of iodine in water increases as the concentrations of potassium iodide increases

Answer is: increasing the concentration of the iodide ions creates disturbance. According to Le Chatelier’s principle, the system will react in a way that tends to reduce the disturbance. The reaction shift in the forward direction, to make more triiodide ions and consume some of the added iodide with aqueous iodine. This causes more solid iodine to dissolve in the solution (increasing concentration).

Reaction: I₂ (aq) + I⁻ (aq) ⇄ I₃⁻ (aq).