Viscosity of liquids

Options

A. increases with increase in temperature
B. is independent of temperature
C. decrease with decreases in temperature
D. decreases with increase in temperature.

Answer

To solve the question regarding the viscosity of liquids and its relationship with temperature, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding Viscosity**:
- Viscosity is defined as the measure of a fluid's resistance to flow. It describes how thick or thin a liquid is. Higher viscosity means the liquid flows less easily.

2. **Effect of Temperature on Viscosity**:
- As the temperature of a liquid increases, the kinetic energy of the molecules also increases. This means that the molecules move faster.

3. **Intermolecular Forces**:
- At higher temperatures, the cohesive forces (intermolecular forces) between the liquid molecules decrease. This is because the increased kinetic energy allows the molecules to overcome these forces more easily.

4. **Resulting Change in Viscosity**:
- With the decrease in cohesive forces, the molecules can move more freely. Therefore, the resistance to flow (viscosity) decreases.

5. **Conclusion**:
- Based on the above points, we conclude that the viscosity of a liquid decreases with an increase in temperature.

6. **Final Answer**:
- The correct option is that viscosity of liquids decreases with an increase in temperature.