What is a salt bridge? Explain the functions of a salt
bridge.

Explanation

A salt bridge is a U-shaped glass tube containig a saturated
solution
of a strong electrolyte, like `KCl,NH_(4)NO_(3), Na_(2)SO_(4)` in a
solidified arar-agar gel. A hot saturated solution of these electrolytes in
5% agar solution is filled in the U-shaped tube and allowed it to cool and
solidify forming a gel.
The functions of a salt bridge are :
(1) It maintains the electrical contact
between the two electrode solutions of the half
cells.
(2) It prevents the mixing of electrode
solutions.
(3) It maintains the electrical neutrality in
both the solutions of two half cells bya flow of
ions.
It eliminates the liquid junction
potential.