Question

Standard electrode potentials of few half-cell reactions are given below :
$Mn{O}_4^{-}+8H^{+}+5e^{-}\to M{n}^{2+}+4H_{2}O$ ; $E^{\circ }=1.51V$
$C{r}_2{O}_7^{2-}+14H^{+}+6e^{-}\to 2C{r}^{3+}+7H_{2}O$ ; $E^{\circ }=1.33V$
$F{e}^{3+}+e^{-}\to F{e}^{2+}$ ; $E^{\circ }=0.77V$
$C{l}_2+2e^{-}\to 2Cl$ ; $E^{\circ }=1.36V$
Based on the above information match the column I with column II and mark the appropriate choice.

	Column I		Column II
(A)	$1mol$ of $Mn{O}_4^{-}$ to $M{n}^{2+}$	(i)	$579000C$
(B)	$1mol$ of $C{r}_2{O}_7^{2-}$ to $2C{r}^{3+}$	(ii)	$193000C$
(C)	$1mol$ of $F{e}^{3+}$ to $F{e}^{2+}$	(iii)	$482500C$
(D)	$1mol$ of $C{l}_2$ to $2C{l}^{-}$	(iv)	$96500C$

• A. $(A)\to (i)$, $(B)\to (ii)$, $(C)\to (iii)$, $(D)\to (iv)$
• B. $(A)\to (ii)$, $(B)\to (iii)$, $(C)\to (i)$, $(D)\to (iv)$
• C. $(A)\to (iii)$, $(B)\to (i)$, $(C)\to (iv)$, $(D)\to (ii)$
• D. $(A)\to (iv)$, $(B)\to (ii)$, $(C)\to (iii)$, $(D)\to (i)$

Answer 1

Answer: (C)

$Mn{O}_4^{-}=96500\times 5F=482500C$
$C{r}_2{O}_7^{2-}=96500\times 6F=579000C$
$F{e}^{3+}=96500\times 1F=96500C$
$C{l}_2=96500\times 2F=193000C$