What is the function of a salt bridge in a galvanic cell?
1. To permit electrons to flow through the solution.
2. To maintain a steady flow of reactants from the cathode to the anode.
3. To form complex ions with the products of oxidation at the anode.
4. To maintain electrical neutrality in the cell.
5. To act as a catalyst.
Would 4 be the answer because the wire permits the flow or would it be 2 because it keeps the flow steady?
No, I think your first answer is the one.
Look at it this way. Draw a cell with a salt bridge between. Make it Zn metal dipping into Zn(NO3)2 solution on the left and Cu metal dipping into Cu(NO3)2 solution on the right. When the reaction starts, Zn goes to Zn^2+ + 2e on the left. On right Cu2+ ions go to Cu metal. So on the left the Zn^2+ ions need NO3^- to hook up with and on the right the Cu^2+ are being removed which leaves an excess of NO3^-. So the excess of nitrate on the right can migrate through the salt bridge and go over to the Zn cell and hook up with those extra Zn^2+ being produced.
The correct answer is 4. The function of a salt bridge in a galvanic cell is to maintain electrical neutrality in the cell.
In a galvanic cell, oxidation takes place at the anode, where electrons are generated and released into the external circuit through a wire. These electrons then flow to the cathode, where reduction occurs. As the reaction progresses, a buildup of positive charge occurs at the anode and a buildup of negative charge occurs at the cathode.
The salt bridge serves to counterbalance this charge buildup by allowing the flow of ions between the two half-cells. It contains an electrolyte solution, typically a salt or gel, that is in contact with both the anode and cathode compartments. The ions in the bridge are able to move freely, allowing positive ions to flow from the salt bridge to the anode compartment to neutralize the accumulating negative charge, and negative ions to flow from the salt bridge to the cathode compartment to neutralize the accumulating positive charge. This maintains overall electrical neutrality in the cell and allows the cell to continue operating.
Therefore, option 4 is the correct answer because the salt bridge's main role is to maintain electrical neutrality in the galvanic cell. Option 2 is incorrect as the salt bridge does not play a role in the steady flow of reactants from the cathode to the anode.