Doubts from a Test Paper

1. If the slope " Z (compressibility factor) vs " P " curve is constant ( Slope = π492.6 atm^-1) at a particular temperature (300 K) and very high pressure, then calculate the diameter if the molecules?

2.The density of vapour of a substance (X) at 1 atm pressure and 500 K is 0.8 Kg/m³. The vapour effuses through a small hole at a rate 4/5 times slower than oxygen under same condition. What is the compressibility factor (Z) of vapour?

3. Calcute relative rate of effusion of SO₂ to CH₄, if the mixture obtained by effusing out a mixture with molar ratio n_SO2n_CH4 = 81 for three effusing steps.

THanks!