P-1 Heat — Science STD 10 — Question

(i) The quantity of heat absorbed or released by a substance to change its state at constant temperature is called latent heat.
(ii) The heat energy absorbed at constant temperature during transformation of solid into liquid is called latent heat of fusion. Latent heat of fusion of ice is 80 cal/g.
(iii) The heat energy absorbed at constant temperature during transformation of liquid into gas is called Latent heat of vapourization. The latent heat of vaporisation of water is 540 cal/g.
(iv) During change of state there is no rise or fall of temperature.