Question

Why do galvanic cells need a salt bridge?

Answer 1

A galvanic cell or voltaic cell is an electrochemical cell that converts the chemical energy of spontaneous redox reactions into electrical energy. A salt bridge is a device that connects the oxidation and reduction halves of an electrochemical cell using a weak electrolyte.

Complete Step By Step Answer:
A galvanic cell is one that generates electricity through a redox reaction. In a galvanic cell, a salt bridge is very significant.
As the electrons are going from one half cell to the other, the objective of a salt bridge is to keep charge balance, not to transport electrons from the electrolyte.
Because the electrode reaction would quickly come to a halt if the salt bridge was not present, the solution in the anode compartment would become positively charged while the solution in the cathode compartment would become negatively charged. As a result of the charge imbalance, the electrode reaction would quickly come to a halt.
Principle of Galvanic cell:
The Gibbs energy of spontaneous redox reaction in the voltaic cell is primarily responsible for the electric work done by a galvanic cell. It consists of two half cells and a salt bridge in most cases. A metallic electrode immersed in an electrolyte is also included in each half cell.
With the help of metallic wires, these two half-cells are externally connected to a voltmeter and a switch. A salt bridge is not always necessary when both electrodes are submerged in the same electrolyte.

Note:
When an electrode is exposed to the electrolyte at the electrode-electrolyte interface in a galvanic cell, the atoms of the metal electrode tend to create ions in the electrolyte solution, leaving the electrons at the electrode behind. As a result, the metal electrode becomes negatively charged. Metal ions in the electrolyte solution, on the other hand, have a tendency to settle on a metal electrode. As a result, the electrode becomes positively charged.