Chapter 18, Problem 18.11P

Interpretation Introduction

Interpretation:

The standard reduction potential for the ${\text{Cr}}^{\text{3+}}\text{/Cr}$ half cell should be calculated from the standard potential of the given galvanic cell.

Concept Introduction:

• Galvanic cells are electrochemical cells convert chemical energy to electrical energy
• Redox reactions where both oxidation and reduction occur simultaneously are central to the working of electrochemical cells.
• In the oxidation half reaction, the substance which could be an atom, molecule or ion, loses one or more electrons while in the reduction half reaction, it gains one or more electrons.
• The measured standard cell potential is the difference between the standard reduction potential at the cathode and that at the anode.

Given:

The galvanic cell is represented as: $\text{Al }\left(\text{s}\right)\left|{\text{ Al}}^{\text{3}+}\left(\text{aq}\right)\right|\left|{\text{ Cr}}^{\text{3}+}\left(\text{aq}\right)\right|\text{ Cr}\left(\text{s}\right)$

Here, $\text{Al }\left(\text{s}\right)|{\text{ Al}}^{\text{3}+}\left(\text{aq}\right)$ forms the anode half-cell and ${\text{Cr}}^{\text{3}+}\left(\text{aq}\right)|\text{ Cr}\left(\text{s}\right)$ forms the cathode half-cell
Standard cell potential ${\text{E}}^{\text{0}}$ = +0.92 V