The E value for the Mn 3 + / Mn 2 + couple is more positive than that of Cr 3 + / Cr 2 + or Fe 3 + / Fe 2 + due to change of [2024]

Question

The $E °$ value for the ${Mn}^{3 +} / {Mn}^{2 +}$ couple is more positive than that of ${Cr}^{3 +} / {Cr}^{2 +}$ or ${Fe}^{3 +} / {Fe}^{2 +}$ due to change of [2024]

Smart Achievers · Accepted Answer

(3)

${}_{25}{Mn} \Rightarrow [Ar] 3 d^{5} 4 s^{2}$

${Mn}^{3 +} \Rightarrow [Ar] 3 d^{4}$

${Mn}^{2 +} \Rightarrow [Ar] 3 d^{5}$

As $d^{5}$ is a half-filled electronic configuration, it is highly stable configuration. Thus, ${Mn}^{3 +}$ has high tendency to get reduced to ${Mn}^{2 +}$ .

Solution

Q.
The $E °$ value for the ${Mn}^{3 +} / {Mn}^{2 +}$ couple is more positive than that of ${Cr}^{3 +} / {Cr}^{2 +}$ or ${Fe}^{3 +} / {Fe}^{2 +}$ due to change of [2024]

1 $d^{5}$ to $d^{4}$ configuration

2 $d^{5}$ to $d^{2}$ configuration

3 $d^{4}$ to $d^{5}$ configuration

4 $d^{3}$ to $d^{5}$ configuration

Ans.
(3)

${}_{25}{Mn} \Rightarrow [Ar] 3 d^{5} 4 s^{2}$

${Mn}^{3 +} \Rightarrow [Ar] 3 d^{4}$

${Mn}^{2 +} \Rightarrow [Ar] 3 d^{5}$

As $d^{5}$ is a half-filled electronic configuration, it is highly stable configuration. Thus, ${Mn}^{3 +}$ has high tendency to get reduced to ${Mn}^{2 +}$ .

Want Us to Email you About Special Offers & Updates?

Solution

Q. The E° value for the Mn3+/Mn2+ couple is more positive than that of Cr3+/Cr2+ or Fe3+/Fe2+ due to change of [2024]

1 d5 to d4 configuration

2 d5 to d2 configuration

3 d4 to d5 configuration

4 d3 to d5 configuration

Ans. (3) Mn25⇒[Ar]3d54s2 Mn3+⇒[Ar] 3d4 Mn2+⇒[Ar] 3d5 As d5 is a half-filled electronic configuration, it is highly stable configuration. Thus, Mn3+ has high tendency to get reduced to Mn2+.