Question

What would happen if no salt bridge were used in an electrochemical cell (like Zn-Cu cell )?

Answer 1

Hint: An electrochemical cell is a battery that can either produce electrical energy from chemical reactions taking place inside it or use electrical energy supplied to it to promote chemical reactions taking place inside it. Chemical energy may be converted to electrical energy or vice versa using these devices.

Complete answer:
In electrochemistry, a salt bridge or ion bridge is a laboratory system that connects the oxidation and reduction half-cells of a galvanic cell (voltaic cell), which is a kind of electrochemical cell. It keeps the internal circuit's electrical neutrality. If there was no salt bridge, the solution in one half cell would accumulate negative charge while the solution in the other half cell accumulated positive charge as the reaction progressed, thereby stopping further reaction and, as a result, energy generation.
Metal ions ( $ Zn^{+2} $ ) produced by electron loss accumulate in one electrode, whereas negative ions ( $ SO_4^{-2} $ ) accumulate in the other. As a result, the remedies will accumulate costs, and the current will cease to flow. In addition, the inner circuit would be incomplete.
A salt bridge essentially prevents the aggregation of positive and negative charges along the corresponding electrodes, allowing for a smooth reaction to occur. It also contributes to the smooth movement of electrons. However, since the electrons are passing from one half cell to the other, the object of a salt bridge is to preserve charge equilibrium rather than to transfer electrons from the electrolyte.

Note:
The salt bridge stops solvent from diffusing or flowing mechanically from one half cell to the other. It inhibits or reduces the potential of a liquid-liquid junction. (When two alternatives come into contact with each other, potential arises.) For two half cells, a salt bridge serves as an electrical contact.