In a galvanic cell, the salt-bridge

Options

A. Does not participate chemically in the cell reaction
B. Stops the diffusion of ions from one electrode to another
C. Is necessary for the occurrence of the cell reaction
D. Ensure mixing of the two electrolytic solutions

Explanation

### Step-by-Step Solution:

1. **Understanding the Galvanic Cell**: A galvanic cell consists of two half-cells, each containing an electrode and an electrolyte solution. In this case, one half-cell contains zinc and zinc ions, while the other contains copper and copper ions.

2. **Role of the Salt Bridge**: The salt bridge is a crucial component that connects the two half-cells. It typically contains a gel or a liquid electrolyte, such as KCl or NH4NO3, which allows ions to flow between the two solutions without mixing them directly.

3. **Purpose of the Salt Bridge**: The primary function of the salt bridge is to maintain electrical neutrality in the half-cells. As the oxidation-reduction reaction occurs, electrons flow from the anode (zinc) to the cathode (copper), leading to a buildup of positive charge in one half-cell and negative charge in the other. The salt bridge allows ions to move in order to balance these charges.

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