Give reason - i) latent heat can't be mesured by thermometer . ii)Pressure has no effect on solid and liquid during phase change.
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Answer:
(i) The energy required for a material to transition from solid to liquid state is the Latent heat of melting, from liquid to gas is the latent heat of vapourisation. Thus a thermometer cannot measure any temperature change when heat is supplied during phase change, otherwise known as latent heat.
(ii) For most of the substances, increasing the pressure when the system is in equilibrium between liquid and solid phases will increase the phase transition temperature. But since water fills a smaller volume when its liquid, rather than solid, it will go to lower melting point, allowing more solid to become liquid.
Eg- When skaters skate on ice, the increased pressure due to their weight causes ice to melt and allow them to move smoothly. When the pressure is removed, the water again freezes.