Question

Evaporation always causes :

• A. Thermal expansion
• B. Liquefaction
• C. Cooling down
• D. All the above

Answer 1

The correct option is C

Cooling down

correct Answer: option(C)-Cooling down

The explanation for the correct answer:

1. Evaporation: The process of changing the liquid state into a vapour state even below its boiling point.
2. Evaporation is a surface phenomenon which means that only those particles of liquid will be converted into a vapour that is present on its surface.
3. Some particles of liquid have higher kinetic energy. this energy can break down the force of attraction and escape from the surface of the liquid in the form of water vapour,
4. Evaporation causes cooling because during the evaporation particles of liquid absorb energy from the surroundings to regain the energy which is lost during the evaporation. the absorption of energy from the surroundings makes the surroundings cool.

The explanation for the incorrect answer:
Option (A)-Thermal expansion: Thermal expansion is the general increase in the volume of a material as its temperature is increased. but Evaporation of a liquid is always accompanied by a decrease in temperature or cooling.

Option (B)-Liquefaction: Liquefication is the process in which particles of gas get converted into liquid.

hence, Evaporation always causes Cooling down-option(C)