[Chemistry Class Notes] Factors Affecting the Rate of Evaporation Pdf for Exam

Evaporation is the natural process where the molecules of a liquid absorb the residual heat present in the liquid and escape in the form of vapour. There is no need to provide external heat to continue this process. It means that evaporation takes place at any temperature. It is a surface phenomenon. Here is the list of the factors affecting the rate of evaporation you should ponder upon. This part of the chapter is very crucial as the questions are quite conceptual. To answer the questions, find out how the factors change to affect the rate of evaporation.

Temperature

The prime factor that determines the rate of evaporation from the surface of a liquid is its temperature. We all know that temperature determines the amount of heat present in a liquid. The heat determines the kinetic energy of the molecules of the liquid. This energy is used to get rid of the intermolecular forces that bind the molecules together. When temperature increases, the heat increases resulting in higher kinetic energy of the molecules. It means that the molecules from the surface will get more energy to break the shackles of intermolecular forces and become vapour. This is the most important among the factors affecting evaporation.

Surface Area

If you concentrate on this factor, you can easily understand that the bigger the surface area, the higher will be the rate of absorption. When the surface molecules get more exposure, they will try to break the intermolecular forces even more. Consider this simple example. A cloth when folded takes more time to dry. If the area of the cloth is spread on the wire, it will dry quicker than in the previous case. This is also the same for evaporation on the liquid surface. When the area of the container is bigger, the rate of evaporation is also higher. This is how the experts simply explain the factors affecting evaporation.

Humidity

Humidity is the amount of water vapour contained in the surrounding atmosphere. The amount of water vapour that air can hold depends on the temperature of the surrounding area. It means that hot air has the capability of carrying more water vapour than colder air. Hence, the amount of moisture contained in air will determine how much more water vapour it can take at that temperature. The higher the humidity, the slower will be the rate of evaporation. If you consider a summer day, you will find that wet clothes dry up faster. On the other hand, clothes take more time to dry on a rainy day as the humidity on that day is higher.

Speed of Wind

If the day is airy, it will take less time for the clothes to dry. The reason is very simple. The air carrying water vapour passes and dryer air comes in to carry more. It means that a windy day will escalate the rate of evaporation. If there is no wind, the rate will be lower. This is how these examples explain factors affecting evaporation properly on this concept page.

Factors affecting the rate of evaporation

When a liquid particle gets in kinetic energy to break its liquid bonds and skate as a gas then the process of evaporation takes place. As each particle that evaporates takes away some energy from the rest of the pack that leads to cooling the remaining liquid particles. So let’s find out the factors that affect evaporation:

• Firstly, a faster rate of evaporation is the result of higher temperatures. Particles move fast at high temperatures so it is more likely for them to have enough energy to break their liquid bonds.

• Secondly, the rate of evaporation increases with the movement of air (breeze) over the liquid. A dense vapour layer over the liquid is formed by the particles that evaporate. To form the liquid Bond many of these ‘escapees’ collide with the liquid.

• The third factor is the dryness of the surrounding air that increases the rate of evaporation. There are a lot of water vapour particles in the surrounding area during a humid day. Therefore the rate of evaporation increases with the increasing dryness of the surrounding.

If you bundle up your washing in a heap to dry will it dry faster?

Wet clothes dry much faster if they are spread properly so that more surface area is exposed to the air. This is because liquid molecules can escape into the surrounding area more easily and at a faster rate.

Why Prefer Using the Concept Pages of ?

The experts at are highly experienced in teaching such concepts to students. They know the exact way to make students understand new concepts by using easy examples. On this concept page, you will find a list of factors affecting evaporation with examples perfectly explained by the experts so that students can easily learn them and score well in the exams. It will also help you revise this part of the chapter very easily before an exam and save a lot of your time.