Question

How is boiling different from evaporation? discuss the factors affecting the rate of evaporation.

Answer 1

Evaporation: Evaporation is the process in which a liquid state of matter (water) is converted into a gaseous state of matter (vapour). In general terms, evaporation is defined as the process in which the liquid state is converted into gas. This process requires heat energy.

• At a given temperature in any gas, liquid or solid, there are particles with different amounts of kinetic energy.
• In the case of liquids, a small fraction of particles at the surface, having higher kinetic energy, is able to break away from the forces of attraction of other particles and gets converted into vapor.
• This phenomenon of change of a liquid into vapors at any temperature below its boiling point is called evaporation

Examples of Evaporation:

• Crystallization
• Drying of clothes

Factors That Affect the Evaporation:

Temperature:

• As the temperature increases, the rate of evaporation also increases.
• Temperature and rate of evaporation are proportional to each other.

Surface area:

• As the surface area increases, the rate of evaporation increases.
• The surface area and rate of evaporation are proportional to each other.

Humidity:

• The rate of evaporation decreases with an increase in humidity.
• Humidity and the rate of evaporation are inversely proportional to each other.

Wind speed:

• An increase in wind speed will increase evaporation.
• Wind speed and rate of evaporation are proportional to each other.