Gas laws and Density of Gas

The mean free path of a gas varies with the density of gas according to the following relation:

The relative density of a gas A with respect to another gas B is 2. The vapour density of the gas B is 20, the vapour density of the gas A is:

Gas laws and there applications

One litre sample of a gas having density 1.20 kg m^(-3) at 1 atm and 0^(@)C was compressed to 500 atm resulting a volume 4cm in violation of Boyle's law The final density of the gas is .

At constant pressure density of a gas is

A gas which obeys the gas laws at all values of temperature and pressure is called _________ .

How can the ideal gas equation be expressed in terms of density of the gas?