n          Latent Heat

 

u        Change of potential energy of substance particle

 

u        During changing state

 

n          When substance changing state

 

u        Latent Heat: absorbed/ released

 

u        X changing substance's temp.

 

n          Specific Latent Heat

 

u        Fusion ice (lf)

 

l          Energy needed to change 1kg ice →water

 

l          X change of temp.

 

l          3.34 x 10^5  J kg^-1

 

u        Vaporization of water (lv)

 

l          Energy needed to change 1kg water →steam

 

l          X change of temp.

 

l          2.26 x 10^6  J kg^-1

 

n          Evaporation

 

u        Fast-moving particles

 

u        Escaping from surface of liquid

 

u        Change of liquid →vapour

 

l          Temp. < Boiling point

 

u        Rate of evaporation↑

 

l          Temp. & surface area of liquid↑

 

l          Density of vapour/ Humidity of air↓

l           Movement of vapour↑