Potassium Iodide or KI is an ionic compound and dissolves to water since the two are polar substances. Like dissolves like. As KI is dissolved into water, the KI molecules dissociates into ions, the K+ and I- ions. Water molecules can stabilize these ions. The K+ ions attracts the negative side of H2O molecules which is the oxygen side while the I- ions attracts the positive side of H2O molecules or the hydrogen side.
