When iron III sulfate Fe2 SO4 3 reacts with potassium iodide KI , the products formed are iron II sulfate FeSO4 , potassium sulfate K2SO4 , and iodine I2 . The balanced chemical equation for the redox reaction is:2 Fe2 SO4 3 + 6 KI 4 FeSO4 + 3 K2SO4 + 3 I2