Which of the following is a correct statement

Options

A. Surface tension of a liquid decreases with increase in temperature
B. Vapour pressure of a liquid decreases with increase in temperature
C. Viscosity of a liquid decreases with decrease in temperature
D. The boiling point of a liquid is independent of the altitude of the place

Explanation

To determine which of the following statements is correct, we will analyze each statement one by one:

1. **Statement 1**: "Surface tension of a liquid decreases with an increase in temperature."
- When the temperature of a liquid increases, the kinetic energy of its molecules also increases. This increased energy causes the molecules to move faster and reduces the intermolecular attractions between them. As a result, the surface tension, which is the force that holds the surface molecules together, decreases. Therefore, this statement is correct.

2. **Statement 2**: "The vapor pressure of a liquid decreases with an increase in temperature."
- This statement is incorrect. As the temperature of a liquid increases, the kinetic energy of the molecules increases, allowing more molecules to escape into the vapor phase. Consequently, the vapor pressure of the liquid increases with an increase in temperature.

3. **Statement 3**: "The viscosity of a liquid decreases with a decrease in temperature."
- This statement is also incorrect. Viscosity is a measure of a liquid's resistance to flow. As temperature decreases, the molecular motion slows down, leading to an increase in viscosity. Therefore, viscosity increases with a decrease in temperature.

4. **Statement 4**: "The boiling point of a liquid is independent of the altitude of the place."
- This statement is incorrect. The boiling point of a liquid is affected by atmospheric pressure, which changes with altitude. At higher altitudes, the atmospheric pressure is lower, resulting in a lower boiling point for liquids.

Based on the analysis above, the only correct statement is:

**Correct Answer**: "Surface tension of a liquid decreases with an increase in temperature."