In the laboratory 10-10 torr is a high vacuum. Use the ideal gas equation of state to estimate the number of molecules in one cubic millimeter of a gas at this pressure when the temperature is 20 °C?
15.2 Air is approximately 80% N2 and 20% O2.
(a) Estimate the average molecular weight of air.
(b) Estimate the root-mean-square speed vrms of air molecules at 30 °C.