Question

The standard electrode potentials of $C{u}^{2+}|C{u}^{+}$ and $C{u}^{+}|Cu$ electrodes are +0.18V and +0.50V. The potential of $C{u}^{2+}|Cu$ electrode is _________.

• A. 0.34V
  
• B. 0.44V
  
• C. -0.34V
  
• D. -0.44V

Answer 1

The correct option is A 0.34V


The given electrode potentials are:
$C{u}^{2+}+e^{-}\rightleftharpoons C{u}^{+},E_1^0=+0.18V;\Delta G_1^0=-1\times 0.18\times F$ unit

$C{u}^{+}+e^{-}\rightleftharpoons Cu,E_2^0=0.50V,\Delta G_2^0=-1\times 0.50\times F$ unit

Let the required electrode potential be x V. Then
$C{u}^{2+}+2e^{-}\rightleftharpoons Cu,E^0=x^0;\Delta G^0=-2\times x\times F$ unit

Now for the electrode reaction

$\Delta G^0=\Delta G_1^0+\Delta G_2^0$

$\Rightarrow (-2\times x\times F)=(-0.18F)+(-0.50F),x=0.34V$