Question

Calculate the value of $E^o$ (in V, upto two decimal points) from the given figure and report your answer as $100\times E^o$.

Answer 1

$Cl{O}_3^{-}+2H_{2}O+4e^{-}\to Cl{O}^{-}+4O{H}^{-};\Delta G_1^0$

$Cl{O}^{-}+H_{2}O+e^{-}\to \frac{1}{2}C{l}_2+2O{H}^{-};\Delta G_2^0$
$\frac{1}{2}C{l}_2+e^{-}\to C{l}^{-};\Delta G_3^0$
From 1, 2 and 3 reactions we get

$Cl{O}_3^{-}+3H_{2}O+6e^{-}\to C{l}^{-}+6O{H}^{-};\Delta G^0$
$\therefore \Delta G^0=\Delta G_1^0+\Delta G_2^0+\Delta G_3^0$
$-6F{E}^0=-4F\times 0.54-F\times 0.45-F\times 1.07$
$\therefore E^0=+\frac{3.68}{6}=+0.61V$
$100\times E^o=61V$.