5.1 Salt Bridge

2.1 Difference between metallic conduction and electrolytic conduction

3.1 Difference Between Electrolytic Cell and Galvanic Cell

5.1 Salt Bridge

9.1 Characteristics of electrochemical series
9.2 Applications of electrochemical series

10.1 Reducing power of Metals
10.2 Oxidising Nature of Non-metals

13.1 Faraday's first law
13.2 Farady's Second Law

15.1 Condition of Equilibrium
15.2 Spontaneity of the Reaction

17.1 Primary Battery or Voltaic Cells (Dry Cells):
17.2 Secondary Cells

It is a connection containing a weak electrolytes between oxidation and reduction half cells in a galvanic cells. It is inverted U shaped glass tube filled with inert electrolyte usually it is $KCl$ or $NaCl$, $KN{O_3}$.

Inert electrolyte is one which does not take part in any electrochemical reaction nor they react with any of the electrolytes present in either of the compartments. For the preparation of Salt bridge, gelatin or agar-agar is dissolved in a hot concentrated aqueous solution of inert electrolyte and solution.

$(i)$ It is used to prevent any net charge accumulation in either compartment or beaker. It should be such that electrons should diffuse through the bridge and enter the left beaker.

$(ii)$ There should be proper diffusional exchange of ions and electrons otherwise charge accumulation would occur and reaction get hamper.

$(iii)$ Salt bridge does not take part in the reaction chemically, but it is necessary for the proper operation of the cell.

$(iv)$ It connects the half cells and complete the circuit which is necessary for the current flow.

$(v)$ It prevents the diffusion and transference of the solutions from one half cell to other.

$(vi)$ It prevents the liquid- liquid junction potential i.e the potential difference between two solution when come together.

$(v)$ It can be replaced by some membrane or some porous partition which allows migration of ions without allowing solutions to intermix.

$(vi)$ It keeps the solutions in half cells electrically neutral. In anodic half cell, positive ions pass into the solution due to which there will be accumulation of extra positive charge in the solution around the anode which prevent the flow of electrons from anode.

But it does not happen because negative ions are provide by salt bridge .Similarly in cathodic half cell, negative ions get accumulate around cathode due to deposition of positive ions by reduction. Sufficient positive ions are given by salt bridge to netualize these negative ions and hence in this way, salt bridge maintains the electrical neutrality.