Chemical Change and Electric Current

Learning Goals

You will learn how electrodes and a salt bridge function in an electrochemical cell.

Synopsis

Electrodes serve as electron sources and sinks in an electrochemical cell. The anode serves as the source of electrons and is the site of oxidation. The cathode serves as the sink for the electrons and is the site of reduction. The anode compartment and the cathode compartment are separated from each other and connected by a salt bridge that allows for ion flow between the compartments. The figure below illustrates the basic principles in action.

Review Question

For the overall reaction Cu²⁺(aq) + Mg(s)--> Mg²⁺(aq) + Cu(s), sketch the cell, give the half-reactions, show the direction of electron flow, and identify the cathode and the anode.