Question

Assertion: Cooling is caused when a liquid evaporates.
Reason: Evaporating liquid particles absorb energy from the surroundings.

• A. Both assertion and reason are correct and reason is correct explanation for assertion.
• B. Both assertion and reason are correct but reason is not correct explanation for assertion.
• C. Assertion is correct but reason is incorrect.
• D. Assertion is incorrect but reason is correct.

Answer 1

The correct option is A

Both assertion and reason are correct and reason is correct explanation for assertion.

The explanation for Assertion statement

• Cooling is caused when a liquid evaporates because the energy taken from the vaporized liquid during evaporation lowers the temperature of the liquid, resulting in evaporative cooling.
• It is because the water molecules absorb the heat of our body and convert into gas molecules.
• The energy is taken away by the molecules when they convert from liquid into gas, and this causes cooling on the original surface.
• Evaporation can generally be defined as the process by which liquid or solid is transformed into vapor.

The explanation for Reason statement

• Evaporating liquid particles absorb energy from the surroundings and this energy is known as Latent heat of vaporization.
• Latent heat of vaporization is a physical property of a substance. It is defined as the heat required to change one mole of liquid at its boiling point under standard atmospheric pressure. It is expressed as kg/mol or kJ/kg.

Hence option A is correct.