Question

Explain the factors on which evaporation depends?

Answer 1

• Evaporation: It is a natural process and is similar to boiling, i.e., water gets converted to water vapors.
• When water is heated, it evaporates. The molecules move and vibrate so quickly that they escape into the atmosphere as molecules of water vapor.
• It is a very important part of the water cycle.

It is affected by the following factors:

• The rate of evaporation increases with an increase in temperature: Higher temperatures lead to an increase in the rate of evaporation as more molecules get kinetic energy to convert the water molecules into vapor as they move rapidly when water is heated. This makes the molecules escape faster.
• The rate of evaporation increases with an increase in the surface area: If the surface area is increased, then the amount of liquid exposed to air is larger. Thus, more molecules can escape with a wider surface area.
• The rate of evaporation increases with the decrease in humidity: The rate of evaporation is inversely proportional to humidity in the air.
• For example: If the air, is already saturated with other water vapors, then there will not be enough room in the air for the liquid to evaporate quickly. The air is saturated with water when the humidity is cent percent and water cannot evaporate.
• The rate of evaporation increases with an increase in the speed of wind: The particles of vapor move away when the speed of the wind increases. This leads to a decrease in the amount of water vapor in the atmosphere.
• For example, we use hand dryers to dry our hands. Here, the wind is expelled from the hand dryer which dries our hands. Clothes dry faster under a fan.
• The rate of evaporation depends upon the nature of the liquid: Some liquids evaporate faster than others because they are more volatile. The force of attraction between their particles is weaker than in other liquids. Thus, they require less heat to overcome the force of attraction between the particles.
• The rate of evaporation increases with the decrease in air pressure: If the air pressure is high on the surface of a body of water, then the water will not evaporate easily. The pressure on the water makes it difficult for it to escape into the atmosphere as vapor. Storms are often high-pressure systems that prevent evaporation.