Question

The efficiency of a cell is $60\%$. Its cell reaction is:
$A\left(s\right)+B^{2+}\left(aq\right)\to A^{2+}\left(aq\right)+B\left(s\right);\Delta H=-240kJ$
The standard electrode potential of cell is

• A. 0.746 V
• B. 0.37 V
• C. 1.48 V
• D. 2.96 V

Answer 1

The correct option is A 0.746 V

$\eta =\frac{\Delta G}{\Delta H}=\frac{60}{100}$
$\Delta G=\frac{-240\times {10}^3\times 60}{100}$
$\Rightarrow -nFE=-144000$
$E=\frac{144000}{2\times 96500}=0.746V$