Air at -73 ^oC. It has 78% of nitrogen and 22% of oxygen only on molar basis. No other chemicals in the air. 1 kg of air is put into 0.1 m³ of airtight container. What is the calculated air pressure by using:

Compressibility chart (fig. A-2 chart): by using Kays Rule

Compressibility chart (fig. A-2 char): by using additive pressures

Redlich-Kwong equation

Van der Waals equation

Ideal gas equation for air: pv = RT, where R = 0.28 for air.