To determine which factors do not affect the conductivity of a solution, we need to analyze the factors that do influence conductivity. The conductivity of a solution is primarily affected by the following factors:
1. **Nature of the Electrolyte**: Strong electrolytes (like NaCl) ionize completely in solution, producing a higher concentration of ions compared to weak electrolytes (like acetic acid), which only partially ionize. Thus, the nature of the electrolyte does affect conductivity.
2. **Concentration of the Solution**: A more concentrated solution contains more ions, which increases conductivity. Conversely, a dilute solution has fewer ions, leading to lower conductivity. Therefore, concentration also affects conductivity.
3. **Temperature**: Increasing the temperature generally increases the mobility of ions in a solution, which in turn increases conductivity. As temperature rises, the kinetic energy of the ions increases, allowing them to move more freely. Thus, temperature is another factor that affects conductivity.
4. **Pressure**: In most cases, pressure does not significantly affect the conductivity of a solution, especially for liquids. The conductivity is more influenced by the factors mentioned above.
Based on this analysis, the factor that does not affect the conductivity of a solution is **pressure**.
### Step-by-Step Solution:
1. **Identify the factors affecting conductivity**: Recognize that conductivity is influenced by the number of ions and their mobility.
2. **Analyze the nature of the electrolyte**: Understand that strong electrolytes have higher conductivity due to complete ionization, while weak electrolytes have lower conductivity.
3. **Examine the concentration of the solution**: Realize that higher concentration means more ions, which leads to increased conductivity.
4. **Consider the effect of temperature**: Acknowledge that increasing temperature enhances ion mobility, thus increasing conductivity.
5. **Evaluate the role of pressure**: Determine that pressure does not significantly alter the conductivity of a solution, particularly in liquids.
### Conclusion:
The factor that does not affect the conductivity of a solution is **pressure**.
