Question

Given below are half cell reactions:
$ MnO _{4}^{-}+8 H ^{+}+5 e ^{-} \rightarrow Mn ^{2+}+4 H _{2} O $
$ E _{ Mn ^{2+} / MnO _{4}^{-}}^{\circ}=-1.510\, V$
$\frac{1}{2} O _{2}+2 H ^{+}+2 e ^{-} \rightarrow H _{2} O ,$
$ E _{ O _{2} / H _{2} O }^{\circ}=+1.223 \,V$
Will the permanganate ion, $MnO _{4}^{-}$liberate $O _{2}$ from water in the presence of an acid ?

• A. No, because $E _{\text {cell }}^{\circ}=-2.733 \,V$
• B. Yes, because $E _{\text {cell }}^{\circ}=+0.287\, V$
• C. No, because $E _{\text {cell }}^{\circ}=-0.287 \,V$
• D. Yes, because $E _{\text {cell }}^{\circ}=+2.733 \,V$

Answer 1

Answer: (B)