Question

The standard reduction potentials of $C{u}^{2+}|Cu$ and $C{u}^{2+}|C{u}^{⨁}$ are 0.337 V and 0.153 V, respectively. The standard electrode potential of $C{u}^{⨁}|Cu$ half cell is:

• A. 0.184 V
• B. 0.827 V
• C. 0.521 V
• D. 0.490 V

Answer 1

Answer: (C)

0.521 V

$C{u}^{2+}+2e^{-}\to Cu...\left(i\right)E_1^{⊝}$

$C{u}^{2+}+e^{-}\to C{u}^{⨁}...\left(ii\right)E_2^{⊝}$

Net equation $(C{u}^{⨁}+e^{-}\to Cu)...\left(iii\right)$

$E_3^{⊝}=\frac{n_1{E}_1^{⊝}-n_2{E}_2^{⊝}}{n_3}=\frac{2\times 0.337-1\times 0.153}{1}=0.521V$

Hence, option C is correct.