How do I measure the amount of cooling caused by evaporation?

Question

I need this for a school experiment. Question is: Measure the amount of cooling caused by evaporation of the following liquids:

(i) water (ii) alcohol (iii) ether

Answer 1

Do you know what a wet bulb thermometer is? This should enable you to demonstrate cooling by evaporation. What you do is tie a tube of cotton cloth onto the mercury bulb of a normal thermometer. Dip the other end of the cloth into the liquid to be examined. The liquid will be drawn up the cloth by capillary action, and evaporate, cooling the thermometer, which will register a lower temperature than a normal thermometer next to the modified one. You can speed up the evaporation and cooling by using a fan to blow air over the thermometers. you compare the temperature of the wet bulb thermometer with the normal thermometer, and also compare the temperature drop between the liquids, water, alcohol and ether.