With increase in temperature the viscosity of

Options

A. liquids increases and of gases decreases
B. liquids decreases and gases increases
C. both liquids and gases increases
D. both liquids and gases decreases

Explanation

### Step-by-Step Solution:

1. **Understanding Viscosity**:
- Viscosity is defined as the measure of a fluid's resistance to flow. It indicates how thick or sticky a fluid is.

2. **Effect of Temperature on Liquid Viscosity**:
- When the temperature of a liquid increases, the kinetic energy of its molecules also increases.
- As the temperature rises, the intermolecular forces (attractions) between the molecules weaken.
- This weakening of intermolecular forces allows the molecules to move more freely, leading to a decrease in viscosity.
- **Conclusion for Liquids**: The viscosity of a liquid decreases with an increase in temperature.

3. **Effect of Temperature on Gas Viscosity**:
- In the case of gases, when the temperature increases, the kinetic energy of the gas molecules increases as well.
- The increased kinetic energy causes the gas molecules to move faster and collide more frequently.
- This increased movement leads to a greater resistance to flow, resulting in an increase in viscosity.
- **Conclusion for Gases**: The viscosity of a gas increases with an increase in temperature.

4. **Final Conclusion**:
- To summarize:
- Viscosity of liquids decreases with an increase in temperature.
- Viscosity of gases increases with an increase in temperature.

5. **Correct Option**:
- Based on the above explanations, the correct answer is that the viscosity of a liquid decreases while the viscosity of a gas increases with temperature.