Evaporation
Conversion of liquid into vapour at all temperatures ( even below boiling point ) is called evaporation .
Boiling
When a liquid is heated gradually , at a particular temperature saturated vapour pressure of the liquid becomes equal to atmospheric pressure , now bubbles of vapour rise to the surface d liquid . This process is called boiling of the liquid .
The temperature at which a liquid boils , is called boiling point The boiling point of water increases with increase in pre sure decreases with decrease in pressure .
Sublimation The conversion of a solid into vapour state is called sublimation . Hoar Frost The conversion of vapours into solid state is called hoar fr .. Calorimetry
This is the branch of heat transfer that deals with the measorette heat . The heat is usually measured in calories or kilo calories .
Principle of Calorimetry
When a hot body is mixed with a cold body , then heat lost by ha is equal to the heat gained by cold body .
Heat lost = Heat gain Thermal Expansion
Increase in size on heating is called thermal expansion . There are three types of thermal expansion .
1 . Expansion of solids 2 . Expansion of liquids 3 . Expansion of gases