Q. $E^{{^\circ}}$ values of ${Mg}^{2 +}$ / Mg is -2.37 V, of ${Zn}^{2 +}$ / Zn is -0.76 V and ${Fe}^{2 +}$ / Fe is -0.44 V. Which of the statements is correct?
A) Zn will reduce ${Fe}^{2 +}$
B) Zn will reduce ${Mg}^{2 +}$
C) Mg oxidises Fe
D) Zn oxidises Fe
Explanation
(a)
Higher the negative value of$E^{{^\circ}}$, more is the reducing power.
The order of $E^{{^\circ}}$ values (negative value) is
$- 2.37\ > \ - 0.76\ > \ - 0.44$
(Mg) (Zn) (Fe)
∴ Mg can reduce both ${Zn}^{2 +}$ and${Fe}^{2 +}$. Zn can reduce ${Fe}^{2 +}$, but not ${Mg}^{2 +}$. Fe cannot reduce Mg and Zn but can oxidize them.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.