There is no force between molecules

The molecule itself does not occupy volume

Can be described by simple formula

There is no ideal gas in reality, but the limit state when the actual gas p→0, v→∞ can be regarded as an ideal gas.

Definition: The amount of heat absorbed or released by a unit amount of a substance when its temperature increases or decreases by 1K (1 degree Celsius).

Mass specific heat capacity c (kJ/(kg▪K))

Volume specific heat capacity c' (kJ/(Nm3▪K))

Molar specific heat capacity Mc (kJ/(kmol▪K))

Specific heat capacity at constant volume

Specific heat capacity at constant pressure

relation

Fixed specific heat capacity

true specific heat capacity

average specific heat capacity

For 1kmol of actual gas

a and b are van der Waals constants, which are related to the size of molecules and intermolecular forces, and vary with different substances.

Definition: At the same temperature and pressure, the ratio of the specific volume v of the actual gas to the specific volume value vid calculated according to the ideal gas equation of state, also called the compressibility coefficient, represented by z

Comparison parameters

van der Waals contrasting equation of state

Contrast equations