Which of the following is incorrect regarding salt bridge solution ?

Options

A. Solution must be a strong electrolyte
B. Solution should be inert towards both electrodes
C. Size of cations and anions of salt should be much different
D. Salt bridge solution is prepared in gelatin or agar-agar to make it semi-solid

Answer

To determine which statement regarding salt bridge solutions is incorrect, we need to analyze the properties and functions of a salt bridge in electrochemical cells. Here’s a step-by-step solution:

### Step 1: Understand the function of a salt bridge
A salt bridge is a device used in electrochemical cells to maintain electrical neutrality by allowing the flow of ions between the two half-cells. It prevents the buildup of charge that could otherwise stop the reaction.

**Hint:** Recall that the primary function of a salt bridge is to maintain charge neutrality in the electrochemical cell.

### Step 2: Identify the composition of a salt bridge
Salt bridges typically contain a gel or liquid solution of an electrolyte, which is usually a salt that does not react with the chemicals in the half-cells. Common examples include potassium chloride (KCl) or sodium sulfate (Na2SO4).

**Hint:** Remember that the electrolyte in a salt bridge should not participate in the redox reactions occurring in the half-cells.

### Step 3: Analyze the mobility of ions
For a salt bridge to function effectively, the velocities of the cations and anions should be similar. This ensures that the ions can migrate at comparable rates, preventing any charge imbalance.

**Hint:** Consider why equal mobility of cations and anions is important for the function of the salt bridge.

### Step 4: Evaluate the size of ions
The size of the cations and anions in the salt bridge should be similar to ensure that they can move freely through the bridge without causing blockages. If the sizes are significantly different, it could lead to uneven migration rates.

**Hint:** Think about how the size of ions affects their movement through the salt bridge.

### Step 5: Identify the incorrect statement
Based on the understanding of the salt bridge, the incorrect statement would be one that contradicts the established properties of the salt bridge. For example, if a statement claims that the sizes of cations and anions should be different, this would be incorrect.

**Hint:** Look for statements that contradict the need for similar ion sizes or the role of the salt bridge in maintaining neutrality.

### Conclusion
After analyzing the properties and functions of the salt bridge, we conclude that the incorrect statement regarding salt bridge solutions is that the sizes of cations and anions should be different. In fact, they should be similar to ensure effective ion migration.

### Summary of the Incorrect Statement
The incorrect statement regarding salt bridge solutions is that the sizes of cations and anions should be different, which is not true; they should be similar for optimal function.

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