Two gases A and B having molecular weights 60 and 45 respectively are enclosed in a vessel. The weight of A is 0.5 g and that of B is 0.2 g . The totla pressure of the mixture is 750 mm . Calculate the partial pressure of the two gases.

Explanation

Given wt. of gas A=0.50 g
mol wt. of gas A=60
Wt, of gas B =0.2 g. Molecular wt. gas B =45
`P_(T) =750 mm`
From Dalton.s law of partial pressure
`P_(A) =P_(T) xx` mole frection of A.
`=750 xx (0.50//60)/((0.50)/(60)+(0.2)/(45))=489.23 mm`.
`P_(T) =P_(A) +P_(B)`
`therefore P_(B) =P_(T)-P_(A)=750-489.23`
`=260.77 mm`.