The negative cell potential (non-spontaneous) is shown by thereaction of Cu+2 with I−. For the reaction, the half- cell reduction reaction is: 2Cu2+(aq)+2e−→2Cu+(aq) The standard potential for the reaction is +0.154 V 2I−(aq)→I2(s)+2e− The standard potential for the reaction is −0.535 V Therefore, the reaction is not possible.