Target Exam

CUET

Subject

Chemistry

Chapter

Physical: Electro Chemistry

Question:

From the given standard reduction potentials, arrange the metals in decreasing order of their reducing power.

(A) $E^0_{Zn^{2+}/Zn} = -0.76V$
(B) $E^0_{Mg^{2+}/Mg}= -2.37 V$
(C) $E^0_{Al^{3-}/Al} = -1.67 V$
(D) $E^0_{Ag^+/Ag}= +0.80 V$

Choose the correct answer from the options given below:

Options:

(A), (B), (C), (D)

(D), (A), (C), (B)

(B), (A), (D), (C)

(B), (C), (A), (D)

Correct Answer:

(B), (C), (A), (D)

Explanation:

The correct answer is Option (4) → (B), (C), (A), (D)

Reducing power of a metal is directly related to its tendency to lose electrons, i.e., to be oxidized.

  • Metals with more negative standard reduction potential ($E^\circ$) are stronger reducing agents.
  • Given $E^\circ$ values:

Metal

$E^\circ$ (V)

Zn

–0.76

Mg

–2.37

Al

–1.67

Ag

+0.80

Arrange in order of increasing $E^\circ$ (more negative → stronger reducing agent)

$\text{Mg (–2.37) > Al (–1.67) > Zn (–0.76) > Ag (+0.80)}$