An evactuated vessel weights 50 g when empty, 144 g when filled with a liquid of density `0.47 g mL^(-1)` and `50.0 g` when filled with an ideal gas at 760 mm Hg at 300 K. The molar mass ideal gas is (given `R = 0.0821 L K^(-1) mol^(-1)`)

Options

A. 61.575
B. 130.98
C. 123.73
D. 47.87

Answer

A

Explanation

Mass of evacuated vessrl = 50 g
Mass of liquid filling the vessel `= 144 - 50 = 94 g`
Volume of liquid = Volume of Vessel.
`= (94 g)/(0.47 gm L^(-1)) = 200 mL`
Volume of gas = 200 mL = 0.2 mL
Pressure of gas = 300 K
Mass of gas `= 50.5 - 50 = 0.5 g`
`PV = nRT = (W)/(M) RT :. M = (WRT)/(PV)`
`= (0.5 xx 0.0821 xx 300)/(1 xx 0.2) = 61.575`