CBSE Class 9th: Matter in Our Surroundings – Evaporation

Evaporation has many applications in our daily life. The rate of evaporation can also be changed in many ways.

A few factors affecting the evaporation are:

• Temperature
• Surface area
• Humidity
• Wind speed

Some of the applications of evaporation are:

• The spirit kept on our hand makes us feel cold because  it undergoes evaporation by absorbing the required latent heat of vaporisation from our hand.
• Water kept in an earthen pot remains cool even in summers. Because the water seeping through the tiny pores of the pot keep on evaporating by taking the require heat of vaporization from the pot and water inside it.
• We feel cool sitting under a fan in summers because the fan increases the rate of evaporation of sweat from our body.
• The wet clothes dry due to the evaporation of water particles present in them.

Quick notes:

• Rate of evaporation increases on increasing the temperature of liquid.
• Rate of evaporation increases on increasing the surface area of liquid.
• Rate of evaporation increases when the humidity of air is low.
• Rate of evaporation increases with the increasing wind speed.

CBSE Class 9: Matter In Our Surroundings - Temperature and Latent Heat