MCQ
The correct order of $E^o_{M^{2+} /M}$ values with negative sign for the four successive elements $Cr, Mn, Fe$ and $Co$ is
- ✓$Mn > Cr > Fe > Co$
- B$Cr < Fe > Mn > Co$
- C$Fe > Mn > Cr > Co$
- D$Cr > Mn > Fe > Co$
✓
Answer
Correct option: A.
$Mn > Cr > Fe > Co$
a
The value of $E_{M^{2}+/ M}^{\circ}$ for given metal ions are
The value of $E_{M^{2}+/ M}^{\circ}$ for given metal ions are
$E_{M n^{2}+/ M n}^{\circ}=-1.18 V$
$E_{C r^{2}+/ C r}^{\circ}=-0.9 V$
$E_{F e^{2+} / F e}^{\circ}=-0.44 V$ and
$E_{C o^{2}+/ C o}^{\circ}=-0.28 V$
The correct order of $E_{M^{2+} / M}^{\circ}$ values without
considering negative sign would be
$M n^{2+}>C r^{2+}>F e^{2+}>C o^{2+}$
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