Question

Cu+
(aq) is unstable in solution and undergoes simultaneous oxidation and
reduction according to the reaction, 2Cu+
(aq) → Cu2+(aq) + Cu(s) . Choose correct E°
for the above reaction if E°Cu2+/Cu=0.34 V and E°Cu2+/Cu+=0.15 V

Answer 1

Is the answer possibly 0.04 V ?

potential E° for  Cu²⁺ / Cu = 0.34 V
                       Cu²⁺/ Cu⁺  = 0.15 V

  2 Cu⁺  (aq) => Cu²⁺  (aq)  + Cu (s)

     Cu  (s)   =>  Cu⁺ (aq)  + e⁻     :  E° =
     Cu⁺ (aq)  =>  Cu⁺² (aq)  + e⁻   :  E° = 0.15 V
     Cu  (s)    =>  Cu⁺²  (aq)  + 2 e⁻    E° :  0.34 V
     Cu⁺ (aq)  +e⁻  =>  Cu  (s)       E° =