On what basis do you classify gases into permanent and temporary gases? Explain these types with example.

On what basis do you classify gases into permanent and temporary gases

1.	On what basis do you classify gases into permanent and temporary gases? Explain these types with example.
Answer» Solution :Based on the values of the CRITICAL temperature, the gases are classified into permanent and temporary gases. (i) Gases having very low critical temperature belong to permanent type. EG: `H_(2),N_(2),He`, etc. (ii) Gases having critical temperature in the ordinary range of temperatures belong to the temporary type. Eg: `NH_(2),CO_(2),SO_(2),HCl`, etc.