Chapter 21, Problem 21.25P

Interpretation Introduction

Interpretation:

The difference between active and inactive electrode and the reason why the inactive electrodes are used has to be identified. The substances which are used as inactive electrodes has to be named.

Concept Introduction:

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.

The electrons flow from anode to cathode through the external wire of the circuit. A salt bridge is used to complete the cell circuit.

Anode: The electrode where the oxidation occurs is called as an anode. It is a negatively charged electrode.

Cathode: The electrode where reduction occurs is called as a cathode. It is a positively charged electrode.

Redox reaction: Redox reaction is a type of chemical reaction, where both the oxidation and reduction occur at the same time. In a redox reaction, one of the reactant is oxidized and the other is reduced simultaneously.

The electric potential applied onto an electrode determines whether it hosts a reduction or oxidation reaction.