The conductivity of a strong electrolyte:

Options

A. increases on dilution
B. decrease on dilution
C. does not change with dilultion
D. depends upon density of electrolytes

Answer

To solve the question regarding how the conductivity of a strong electrolyte varies with dilution, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Conductivity**:
- Conductivity is the ability of a substance to conduct electricity. It depends on the nature of the electrolyte, temperature, pressure, and concentration of the electrolyte.

**Hint**: Remember that conductivity is linked to how well ions can move in solution.

2. **Characteristics of Strong Electrolytes**:
- Strong electrolytes, such as NaCl, dissociate completely in solution. This means they break down into their constituent ions (e.g., Na⁺ and Cl⁻) when dissolved in water.

**Hint**: Strong electrolytes dissociate 100% in solution, which is a key characteristic.

3. **Effect of Dilution on Concentration**:
- When a strong electrolyte is diluted, the total number of ions remains constant, but the volume of the solution increases.
- Concentration is defined as the number of ions per unit volume. Therefore, as the volume increases due to dilution, the concentration of ions decreases.

**Hint**: Think about how adding more solvent affects the concentration of ions in the solution.

4. **Relationship Between Concentration and Conductivity**:
- Conductivity is directly related to the concentration of ions in the solution. As the concentration of ions decreases (due to dilution), the conductivity also decreases.

**Hint**: Remember that more ions in solution means better conductivity.

5. **Conclusion**:
- Therefore, we conclude that the conductivity of a strong electrolyte decreases upon dilution because the concentration of ions decreases while the number of ions remains constant.

**Hint**: The key takeaway is that dilution reduces the concentration of ions, which in turn reduces conductivity.

### Final Answer:
The conductivity of a strong electrolyte decreases with dilution.