Consider the cell at 25 ° C Zn| Zn ^ 2 + (aq), (1M) ‖ Fe ^ 3 + ( aq...

${E}_{cell}^{0} = 0 . 77 - \left(0 . 76\right)$

$= 1 . 53V$

$1 . 50 = 1 . 53 - \dfrac{0 . 06}{2}log{\left(\dfrac{{Fe}^{2 +}}{{Fe}^{3 +}}\right)}^{2}$

$\log \left(\dfrac{{Fe}^{2 +}}{{Fe}^{3 +}}\right) = \dfrac{0 . 03}{0 . 06} = \dfrac{1}{2}$

$\dfrac{\left[{Fe}^{2 +}\right]}{\left[{Fe}^{3 +}\right]} = {10}^{1 / 2} = \sqrt{10}$

$\dfrac{\left[{Fe}^{3 +}\right]}{\left[{Fe}^{2 +}\right]} = \dfrac{1}{\sqrt{10}}$

$\dfrac{\left[{Fe}^{3 +}\right]}{\left[{Fe}^{2 +}\right] + \left[{Fe}^{3 +}\right]} = \dfrac{1}{1 + \sqrt{10}} = \dfrac{1}{4 . 16}$

$= 0 . 2402$

$= 24 \times {10}^{- 2}$