A sample of air contains only `N_(2), O_(2)` and `H_(2)O`. It is saturated with water vapours and the total pressure is 640 torr. The vapurs of water is 40 torr and the molar ratio of `N_(2) : O_(2)` is `3 : 1`. The partial pressure of `N_(2)` in the sample is

A sample of air contains only N_(2)O_(2) and H_(2)O . It is saturated with water vapours and total pressure is 640 torr. The vapour pressure of water is 40 torr and the molar ratio of N_(2):O_(2) is 3:1. The partial pressure of N_(2) in the sample is :

A sample of air contains only N_(2), O_(2), and H_(2)O . It saturated with water vapours and total pressure is 6 "torr" . The vapour pressure of water is 40 "torr" and the mol ratio of N_(2):O_(2) is 3:1 . The partial pressure of N_(2) in the sample is

A sample of air contains Nitrogen, Oxygen and saturated with water vapour under a total pressure of 640 mm. If the vapour pressure of water at that temperature is 40 mm and the molecular ratio of N_(2): O_(2) is 3:1, the partial pressure of Nitrogen in the sample is

If air contains N_(2) and O_(2) in volume ratio 4 : 1 , the average vapour density of air is: