Question

Which of the following is an incorrect statement for liquid?

• A. Surface tension of a liquid decreases with increase in temperature
• B. Viscosity of a liquid decreases with decrease in temperature
• C. Vapour pressure of a liquid increases with increase in temperature
• D. Droplets of a liquid on a flat surface are slightly flattened due to gravity

Hint:

Viscosity is inversely proportional to temperature. Honey flows faster when heated.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Properties of liquids vary with temperature. Viscosity is the resistance to flow.

Step 2: Detailed Explanation:
• (A) Correct: As temperature increases, molecular kinetic energy increases, overcoming intermolecular forces, so surface tension decreases. • (B) Incorrect: As temperature decreases, molecular kinetic energy decreases, intermolecular forces become more significant, and viscosity increases. So, viscosity decreases with an increase in temperature, not a decrease. • (C) Correct: As temperature increases, more molecules have enough energy to escape the liquid phase, so vapor pressure increases. • (D) Correct: Gravity pulls on the liquid droplet, causing it to flatten slightly, especially if it's large.

Step 3: Final Answer:
The incorrect statement is that viscosity decreases with a decrease in temperature, which corresponds to option (B).