Chapter 19, Problem 111AP

Interpretation Introduction

Interpretation:

The pressure of hydrogen gas required to maintain equilibrium at ${25}^{\text{o}}\text{C}$ is to be determined.

Concept introduction:

According to the standard reduction potential values, the electrode that has a less negative reduction potential will act as a cathode and undergo reduction. However, if the reduction potential of the electrode is more negative, then that electrode will act as an anode and undergo oxidation.

The standard reduction potential of a galvanic cell may be calculated in terms of standard reduction potential of cathode and anode as the relation mentioned below:

$E_{cell}^o=E_{cathode}^o-E_{anode}^o$

According to the Nernst equation, the relation between emf, standard cell potential, and reaction quotient at $298\text{K}$ will be as follows:

$E=E_{cell}^o-\frac{\text{0}\text{.0592V}}{n}\log Q$

Here, $E$ is the emf of the cell, $E_{cell}^o$ is the standard reduction potential of the cell, $Q$ is the reaction quotient, and $n$ is the electron change in the half-cell reactions.