Q. The E$^\circ$ 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
A) d$^4$ to d$^5$ configuration
B) d$^3$ to d$^5$ configuration
C) d$^5$ to d$^4$ configuration
D) d$^5$ to d$^2$ configuration
Explanation
[Solution by Claude - not from source] $Mn^{3+}$ ($d^4$) is reduced to the stable half-filled $Mn^{2+}$ ($d^5$), making the couple strongly positive. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.