A one litre glass bulb is evacuated and weighed. The weight is 500 g. It is then filled with an ideal gas at 1 atm pressure at 312.5 K. The weight of the filled bulb is 501.2 g. The molar weight of the gas is : `(R = 8 xx 10^(-2) L atm K^(-1) mol^(-1))`

Options

A. 28
B. 32
C. 30
D. 24

Answer

C

Explanation

Mass fo gas `= 501.2 - 500 = 1.2 g`
`PV = (w)/(m) RT`
`m = w (RT)/(PV) = (1.2 xx 0.08 xx 312.5)/(1 xx 1) = 30 g mol^(-1)`