With rise in temperature, viscosity of a liquid

Options

A. increases
B. decreases
C. remains constant
D. may increase or decrease

Answer

### Step-by-Step Solution:

1. **Understanding Viscosity**:
- Viscosity is defined as the measure of a fluid's resistance to flow. A liquid with high viscosity resists flow more than a liquid with low viscosity.

2. **Factors Affecting Viscosity**:
- Viscosity depends on the intermolecular forces of attraction between the molecules of the liquid. Stronger intermolecular forces result in higher viscosity, while weaker forces lead to lower viscosity.

3. **Effect of Temperature on Viscosity**:
- The relationship between temperature and viscosity is inversely proportional. This means that as temperature increases, viscosity decreases.

4. **Reasoning Behind the Inverse Relationship**:
- When the temperature rises, the average kinetic energy of the molecules in the liquid increases.
- Higher kinetic energy causes the molecules to move faster, which reduces the effect of intermolecular forces.

5. **Conclusion**:
- As a result of the increased kinetic energy and decreased intermolecular forces, the viscosity of the liquid decreases with an increase in temperature.

6. **Final Answer**:
- Therefore, with a rise in temperature, the viscosity of a liquid decreases.