Question

Distinguish between an ideal gas and a real gas.

Answer 1

Ideal gas		Real gas
1.	Molecules of an ideal gas behave as ideal particles, i.e., they are like geometrical points without size and structure.	1.	Molecules of a real gas have finite size and structure.
2.	There are no intermolecular forces.	2.	Intermolecular forces are non-zero.
3.	Molecules of an ideal gas have only translational motion.	3.	Polyatomic molecules have in general, translational, vibrational and rotational motion.
4.	In the absence of intermolecular forces, the internal energy of the gas is only kinetic.	4.	Due to the intermolecular forces, the internal energy of the gas is (potential energy + kinetic energy).
5.	There are no intermolecular collisions.	5.	There are intermolecular collisions and, under normal conditions, the collision frequency is very high.
6.	An ideal gas cannot be liquefied.	6.	A real gas can be liquefied and also solidified in many cases, by increasing pressure and reducing temperature.