Question

Evaporation is the process of a liquid changing into vapour :

• A. At$100°\mathrm{c}$
• B. Only at its boiling point
• C. Below its boiling point
• D. Only at room temperature

Answer 1

The correct option is C

Below its boiling point

Correct Answer: Option (C) below its boiling point

The explanation for the correct answer:

1. Boiling Point: The temperature at which liquid gets converted into gases.
2. Evaporation: The process of changing the liquid state into a vapour state even below its boiling point.
3. Evaporation is a surface phenomenon which means that only those particles of liquids change into vapours that are present at the surface due to an increase in temperature or pressure, it changes liquid into a gaseous state before reaching boiling point.

The explanation for the incorrect answer:

1. Option (A) at$100°\mathrm{c}$: Evaporation can takes place at any temperature below its boiling point. The boiling point of water is $100°\mathrm{c}$ . thus, evaporation does not take place at$100°\mathrm{c}$.
2. Option (B) Only at its boiling point: Evaporation can takes place at any temperature below its boiling point.
3. Option (D) only at room temperature: Evaporation can takes place at any temperature below its boiling point.

Evaporation is the process of a liquid changing into vapour is Option (C) below its boiling point.