Question

For a cell given below :

$Ag|Ag^+||Cu^{2+}|Cu$

$\overset{-}{Ag^+ + e^-} \to \overset{+}{Ag} \,\,\, E^{\circ} = x$

$Cu^{2+} + 2e^- \to, \,\,\, E^{\circ} = y$

$E^{\circ}$ cell is :

• A. $x + 2 y$
• B. $2 x + y$
• C. $y - x$
• D. $y - 2 x$

Answer 1

Answer: (C)

At LHS (oxidation) $2 \times\left( Ag \longrightarrow Ag ^{+}+e^{-}\right)$
$E_{ ox }^{-}=-x$

At RHS (reduction) $Cu ^{2+}+2 e^{-} \longrightarrow Cu$
$E^{\circ}_{red} = + y$
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$2Ag + Cu^{2+} to Cu + 2Ag^+ , E^{\circ}_{red} = (y - x)$
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Note : $E^{\circ}$ values remain constant when half-cell equation is multipled/divided.