Question

Seminar on evaporation,boiling

Answer 1

Evaporation is the process of a substance in a liquid state changing to a gaseous state due to an increase in temperature or pressure or both. Evaporation is a fundamental part of the water cycle and is constantly occurring throughout nature.

Boiling is the rapid vaporization of a liquid, which occurs when a liquid is heated to its boiling point, the temperature at which the vapor pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere.

Evaporation and boiling look like similar processes because both start with a liquid and end up with a gas. But there are some important differences between them :

Evaporation occurs on the surface of the liquid whereas boiling occurs at the entire length of liquid. There is formation of bubbles in boiling, but bubbles are not seen in evaporation.

Boiling occurs rapidly whereas evaporation occurs slowly.
The motion of particles is fast in boiling whereas in evaporation few particles move slowly and few at a faster rate.

Evaporation occurs at any temperature whereas boiling occurs at a specific temperature.