Interconversion Of Matter
*Latent heat:
The amount of heat required to change the state of matter from one state to another without rise in temperature is known as latent heat of that substance.
Latent heat is of two types:
(i) Latent heat of fusion: The amount of heat required to change the state of matter from solid state to liquid state without rise in temperature is known as latent heat of fusion.
(ii) Latent heat of vaporisation: The amount of heat required to change the state of matter from liquid state to gaseous state without rise in temperature is known as latent heat of vaporisation.
Some substances may exist in all the three states of matter in different conditions, for example, water can exist in three states of matter:
(i) in solid state as ice.
(ii) in liquid state as water.
(iii) in gaseous state as water vapours or steam.
This inter conversion of matter can be achieved by the following two ways :
(a) by changing the temperature.
(b) by changing the pressure.
Now question arises, that :
How does the matter convert from one state to another by changing temperature & Pressure ?
or
What is the effect of change of temperature and pressure on three states of matter ?
Common Unit of Temperature and SI Unit of Temperature
Common unit of measuring temperature is degree Celsius (°C). The SI unit of measuring temperature is Kelvin which is denoted by the symbol K. The Kelvin scale and Celsius scale of temperature are interconvertible and the relation can be written as : Temperature in Kelvin (K) scale = Temperature in Celsius (°C) scale + 273.