Question

Which of pair of ions will act as strong oxidising agents?

• A. $M{n}^{3+}$ and $C{o}^{3+}$
• B. $M{n}^{3+}$ and $S{c}^{3+}$
• C. $C{o}^{3+}$ and $S{c}^{3+}$
• D. $C{r}^{3+}$ and $T{i}^{3+}$

Answer 1

The correct option is A $M{n}^{3+}$ and $C{o}^{3+}$

Oxidising agents will oxidise other compounds and itself get reduced. Thus, higher value of $E_{M^{3+}/M^{2+}}^0$ indicates its high ability to get reduced from $M^{3+}$ to $M^{2+}$.
Hence, ions which has high positive $E_{M^{3+}/M^{2+}}^0$ value will act as strong oxidising agent.

In 3d-series, Managane has high $E_{M^{3+}/M^{2+}}^0$ value because $M{n}^{2+}$ is stable due to half filled d-orbital.
Also, Cobalt has high $E_{M^{3+}/M^{2+}}^0$ value to higher third ionisation value.

Hence, $M{n}^{3+}$ and $C{o}^{3+}$ will act as strong oxidising agents.