How does the boiling point affect evaporation?

1 Answer

See explanation.


Boiling point and evaporation have an inverse relationship, that is, the higher the boiling point of a substance, the lower is the rate of its transformation from liquid to gas (or evaporation).

When the particles of a substance (usually a liquid) is heated up, its particles absorb the energy provided thereby increasing their kinetic energy resulting to more movement of the individual particles. There comes a period when the violent vibrations created breaks their bonds with other particles.

Examples of these bonds are the intermolecular bonds, e.g., hydrogen bonds, van der Waal's forces. The particles are then released in the form of vapor (gaseous phase of the liquid). These vapor particles now exert pressure in the container called "vapor pressure".

When the pressure of these vapor particles equalizes existing atmospheric pressure, the liquid then starts to boil. And we call the temperature when this is visually observed as "boiling point".

A substance with strong intermolecular bonds require more energy to break these bonds, thus, are described as "with high boiling point". These substances are also described as "nonvolatile" because spontaneous evaporation, like with rubbing alcohol, is not possible.

Hope this helped!