An enclosure of volume V contains a mixture of 8 g of oxygen, 14 g of nitrogen and 22 g of carbon- dioxide at absolute temperature T. The pressure of the mixture of gases is (R is universal gas constant)
5RT4V
The pressure exerted by a gas is given by
P = nRTV
= massmolecular weight × RTV
Pressure exerted by oxygen P1 = 832RTV = 14RTV
Pressure exerted by oxygen P2 = 1428RTV = 12RTV
Pressure exerted by carbon dioxide
P3 = 2244RTV = 12RTV
From Dalton's law of partial pressures, the total pressure exerted by the mixture is given by
P = P1 + P2 + P3
=14RTV +12RTV + 12RTV
= 5RT4V,
which is choice (c)