Salt bridge

Definition

A salt bridge is a device used in electrochemical cells to maintain electrical neutrality by allowing the transfer of ions. It typically consists of a tube filled with a salt solution or gel that connects the two half-cells.

5 Must Know Facts For Your Next Test

1. The primary function of a salt bridge is to prevent the buildup of charge by allowing ions to flow between the two half-cells.
2. Without a salt bridge, the electrochemical cell would quickly stop functioning due to charge imbalance.
3. Common salts used in salt bridges include KCl, KNO3, and Na2SO4 because they do not react with other chemicals in the cell.
4. Salt bridges can be made from materials like agar-agar or glass tubes filled with electrolyte solutions.
5. Maintaining electrical neutrality is essential for continuous electron flow through the external circuit.

Review Questions

• What is the primary function of a salt bridge in an electrochemical cell?
• Name three common salts that are used in constructing a salt bridge.
• Why is maintaining electrical neutrality important in galvanic cells?

Related terms

Electrolyte:

A substance that produces ions when dissolved in water and conducts electricity.

Galvanic Cell:

An electrochemical cell that derives electrical energy from spontaneous redox reactions taking place within it.

Oxidation:

$\text{The loss of electrons during a reaction by a molecule, atom, or ion.}$