What is the formula for heat capacity?

Aug 26, 2022, 16:45 IST

HEAT CAPACITY

Heat capacity of a system is defined as the quantity of heat required to raise the temperature of the system by one degree.

where,

Physics Wallah Chemistry Doubts page consist of more questions for reference. 

C = Heat capacity

q = Heat absorbed

T₁ = Initial temperature

T₂ = Final temperature

If the amount of substance taken is 1 gm then C is called specific heat capacity and if the amount of substance taken is 1 mole then C is called molar heat capacity.

at constant volume 

at constant pressure 

Note:

(i) Lighter elements have higher specific heat capacity and vice – versa. Specific heat of same substance in solid, liquid or gaseous state will be different.

(ii) Specific heat of water in cal / goC is 1, that of ice is 0.5, and that of steam is 0.47.

(iii) Boiling point of a liquid rises on increasing pressure whereas melting point can increases in some cases and can decreases also depending upon contraction and extension on melting. e.g. Melting points of ice and rubber (which contract on melting) fall with increase in pressure. Melting point of wax and sulphur (which expand on melting) rise with rise in pressure.

(iv) At Boyle’s temperature, all real gases behave like a perfect gas.

(v) At low pressure and high temperature a gas may show behaviour of ideal gas.

(vi) A real gas spread in a very large volume also behaves as a real gas.

(vii)Saturated vapours do not obey gas laws whereas unsaturated vapours obey gas laws.