Chapter 21, Problem 21.8P

Interpretation Introduction

Interpretation:

The electrochemical cell that has $\Delta G_{sys}<0$ and the electrochemical that shows increase in free energy has to be identified.

Concept Introduction:

The Gibb’s free energy change associated with a process shall be less than 0, if the process is spontaneous.

The Standard Gibb’s free energy change and the standard cell potential are related as followed:

$\text{Δ}°\text{G}\text{=}\text{-nFE}{°}_{\text{cell}}$

n - Number of electrons involved per equivalent of the net redox reaction in the cell

F - Faraday’s Constant (96500 C)

$\text{E}{°}_{\text{cell}}$ - Standard cell potential.

Oxidation: If electrons are moved from a species during a chemical reaction. The species whose electrons are removed is said to be oxidized.

Reduction: If electrons are gained to a species during a chemical reaction. The species which gets electrons are said to be reduced.

Redox reaction: It occurs when oxidation and reduction takes place at the same time in a chemical reaction.

An electrochemical cell is a device in which a redox reaction is used to convert chemical energy into electrical energy. Such device is also known as the galvanic or voltaic cell.

Galvanic cell consists of two half-cells. The redox reaction occurs in these half-cells. The half-cell in which the reduction reaction occurs is known as the reduction half-cell, whereas the half-cell in which the oxidation reaction occurs is known as the oxidation half-cell.