Mark the statement which is correct:

Options

A. Surface tension of a liquid increases with temperature
B. Addition of chemicals reduces the surface tension of a liquid
C. Stalagmomter is used for measuring viscosity of the liquid.
D. Viscosity of the liquid does not depend on intermolecular forces.

Answer

To solve the question, we need to analyze each statement provided and determine which one is correct.

### Step-by-Step Solution:

1. **Evaluate the first statement**: "Surface tension of the liquid increases with temperature."
- **Analysis**: This statement is incorrect. As temperature increases, the kinetic energy of the molecules also increases, which leads to a decrease in surface tension.
- **Conclusion**: This statement is false.

2. **Evaluate the second statement**: "Addition of chemical reduces the surface tension of liquid."
- **Analysis**: This statement is generally true. Surfactants or certain chemicals can lower the surface tension of a liquid by disrupting the intermolecular forces at the surface.
- **Conclusion**: This statement is true.

3. **Evaluate the third statement**: "Staglometer is useful for measuring viscosity of liquid."
- **Analysis**: This statement is correct. A Staglometer is indeed an instrument used to measure the viscosity of liquids.
- **Conclusion**: This statement is true.

4. **Evaluate the fourth statement**: "Velocity of a liquid does not depend upon the intermolecular forces."
- **Analysis**: This statement is incorrect. The velocity of a liquid is influenced by intermolecular forces, as they affect the viscosity of the liquid. Higher intermolecular forces typically lead to higher viscosity, which can slow down the flow of the liquid.
- **Conclusion**: This statement is false.

### Final Conclusion:
The correct statements are:
- B: "Addition of chemical reduces the surface tension of liquid."
- C: "Staglometer is useful for measuring viscosity of liquid."

### Answer:
The correct options are B and C.

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