Difference Between Evaporation And Boiling

What Is Evaporation?                                      

Evaporation is a natural process and it is similar to boiling, but the liquid form changes into gaseous form when there is an increase in either temperature or pressure or both. When the molecules of liquid collide, they transfer energy to each other based on how they collide with each other. When a molecule near the surface absorbs enough energy to overcome the vapor pressure, it will escape and enter the surrounding air as a gas. When evaporation occurs, the energy removed from the vaporized liquid will reduce the temperature of the liquid, resulting in evaporative cooling.

What You Need To Know About Evaporation

• Evaporation is a natural process and it is similar to boiling, but the liquid form changes into gaseous form when there is an increase in either temperature or pressure or both.
• Evaporation can occur at any temperature of the liquid.
• Evaporation occurs only from the top most layer of the liquid.
• Most of the time, energy for evaporation is supplied by the atmosphere or surrounding.
• Evaporation usually occurs on the surface of the liquid being heated up.
• Evaporation results in cooling of the liquid.
• The larger surface area offers fast evaporation of the liquid i.e rate of evaporation is directly proportional on the surface area temperature.
• Evaporation takes place as long as the air above the liquid remains unsaturated.
• There is no formation of bubbles in evaporation.
• Evaporation is a quiet process.
• Temperature of the liquid decreases gradually due to evaporation.
• Evaporation is a very slow vaporization process.

What Is Boiling?

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

There are two types of boiling: critical heat flux boiling where the boiling surface is heated above a certain critical temperature and a film of vapor forms on the surface. The other is nucleated boiling, where small bubbles of vapor form at discrete points.

What You Need To Know About Boiling

• Boiling is vaporization of liquid into gas due to continuous heating. Most of the times it is not natural.
• Boiling of a specific liquid occurs only at a particular temperature (boiling temperature) at particular pressure.
• Boiling occurs from the entire liquid once its temperature reaches boiling temperature.
• Usually external source of energy is required for boiling to happen.
• Boiling usually occurs on the entire mass of the liquid that is being heated.
• Boiling results in the heat and does not cause cooling.
• The boiling point of the water is 100^oc and the temperature does not increase further even though there is continuous supply of heat.
• Boiling takes place when the internal liquid pressure is equal to the external pressure (ambient pressure).
• There is formation of bubbles in boiling.
• Due to continuous bubble formation and collapse, boiling is a relatively noisy process.
• During boiling, temperature of the liquid remains constant.
• Boiling occurs rapidly.

Also Read: Difference Between Evaporation And Transpiration

Difference Between Evaporation and Boiling In Tabular Form