give four example to show cooling caused by evaporation also describe the reason behind it .
Answers
Explanation:
- when tea is poured into a saucer when it is very hot it is exposed to a large area and causes evaporation n the tea becomes cool. 2.In summer seasons the water gets cool in a earthen pot because it has fine pores in it through which water seeps out gets evaporated . 3. when we sweat n sit under a fan we feel cool4when we apply deodorant..we feel cool...5.when we apply acetone on our nails to remove nail polish we feel cool......
How does Evaporation Cause Cooling?
Evaporation causes cooling naturally. The underlying principle behind this is, in order to change its state, the matter must either gain or lose energy. In the case of change of phase from liquid to gas, molecules of matter require energy to overcome their potential energy by their kinetic energy. So, the liquid takes this energy from its surroundings.
Generally, when energy transfer occurs, it results in an increase or decrease in temperature of the substance, depending on whether the energy is being transferred from the substance to the surroundings or vice versa. However, there are exceptions to this rule.
Although there is an increase in temperature of the substance until the boiling point is attained during evaporation, phase change results in no observable heat transfer.
The molecules of the substance absorb heat energy continuously from the surroundings and thus cool the surroundings until they reach the boiling point, after which they start to break free from the liquid and turn into vapour. Since there is no change in temperature till the evaporation process is complete i.e. the entire liquid gets converted into vapour, the amount of energy required for this phase change is called the latent heat of vaporization, where the word ‘latent’ means ‘hidden’, meaning this heat will not change the temperature reading on a thermometer