Ideal Gas:
1.It obeys ideal gas equation pV = µRT at all temperatures and pressures.
2.The volume of the molecules of an ideal gas is zero.
3.There is no intermolecular force between the molecules.
4.There is no intermolecular potential energy (U) because intermolecular force (F) is zero.
5.It has only kinetic energy.
6.At absolute zero, the volume pressure and internal energy become zero.
Real Gas:
1.It does not obey pV = µRT at all values of temperature and pressure.
2.The volume of the molecules of a real gas is non-zero.
3.There is intermolecular force of attraction or repulsion depending on whether intermolecular separation is larger or small. Potential energy (U) does not equal to zero as intermolecular force (F) is not zero.
4.It has both kinetic and potential energy.
5.All real gases get liquified before reaching absolute zero. The internal energy of the liquefied gas is not zero.