Whichof the following statements are correct ?
(a) With rise in temperature, surface tension of a liquid increases.
(b) The rise of a liquid in a capillary is due to the phenomenon of diffusion.
(c ) The boiling point of water is lower is Shimla than in Jalandhar.
(d) The viscosity of a liquid is generally more than that of a gas.

Answer

To determine which statements are correct, let's analyze each one step by step:

### Step 1: Analyze Statement (a)
**Statement:** With rise in temperature, surface tension of a liquid increases.

**Analysis:** Surface tension is the result of intermolecular forces. As temperature increases, the kinetic energy of the molecules increases, causing them to move more vigorously. This results in a weakening of the intermolecular forces, leading to a decrease in surface tension.

**Conclusion:** This statement is **incorrect**.

### Step 2: Analyze Statement (b)
**Statement:** The rise of a liquid in a capillary is due to the phenomenon of diffusion.

**Analysis:** The rise of liquid in a capillary tube is primarily due to capillary action, which is influenced by surface tension and adhesive forces between the liquid and the walls of the capillary. Diffusion, on the other hand, refers to the movement of particles from an area of higher concentration to an area of lower concentration and is not the mechanism behind capillary rise.

**Conclusion:** This statement is **incorrect**.

### Step 3: Analyze Statement (c)
**Statement:** The boiling point of water is lower in Shimla than in Jalandhar.

**Analysis:** Shimla is at a higher altitude compared to Jalandhar. As altitude increases, atmospheric pressure decreases. The boiling point of a liquid is directly related to the atmospheric pressure; lower pressure results in a lower boiling point. Therefore, the boiling point of water in Shimla will indeed be lower than in Jalandhar.

**Conclusion:** This statement is **correct**.

### Step 4: Analyze Statement (d)
**Statement:** The viscosity of a liquid is generally more than that of a gas.

**Analysis:** Viscosity is a measure of a fluid's resistance to flow. Liquids generally have stronger intermolecular forces compared to gases, which means they resist flow more than gases do. Therefore, the viscosity of liquids is typically greater than that of gases.

**Conclusion:** This statement is **correct**.

### Final Summary:
- Statement (a): Incorrect
- Statement (b): Incorrect
- Statement (c): Correct
- Statement (d): Correct

### Correct Statements:
- (c) The boiling point of water is lower in Shimla than in Jalandhar.
- (d) The viscosity of a liquid is generally more than that of a gas.

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