The overall reaction 2Co3+(aq) + 2Cl–(aq) → 2Co2+(aq) + Cl2(g) has the standard cell voltage E°cell= 0.46 V. Given E° = 1.36 V for the reaction Cl2(g) + 2e–→ 2Cl–(aq), calculate the standard reduction potential for the following the half reaction at 25°C:
Co3+ + e–→ Co2+
◦ 1.82 V
◦ –0.90 V
◦ 0.90 V
◦ –1.82 V
◦ –1.36 V