Question

The standard electrode potential (E°) values of Al³⁺/Al, Ag⁺/Ag, K⁺/K and Cr³⁺/Cr are −1.66 V, 0.80 V, −2.93 V and −0.74 V, respectively. The correct decreasing order of reducing power of the metal is ______.

Options

• Al > K > Ag > Cr

• Ag > Cr > Al > K

• K > Al > Cr > Ag

• K > Al > Ag > Cr

Answer 1

The standard electrode potential (E°) values of Al³⁺/Al, Ag⁺/Ag, K⁺/K and Cr³⁺/Cr are −1.66 V, 0.80 V, −2.93 V and −0.74 V, respectively. The correct decreasing order of reducing power of the metal is K > Al > Cr > Ag.

Explanation:

Reducing power of a metal is inversely related to its standard reduction potential (E°).

A more negative E° indicates a stronger tendency to lose electrons, which in turn means a stronger reducing agent.

Given E° values:

K⁺/K = −2.93 V

Al³⁺/Al = −1.66 V

Cr³⁺/Cr = −0.74 V

Ag⁺/Ag = +0.80 V

So, reducing power order is K > Al > Cr > Ag.