A rigid container containing 5 mole `H_(2)` gas at same pressure and temperature. The gas has been allowed to escape by simple process from the container due to which pressure of the gas becomes half of its initial pressure and temperature become `(2"/"3)rd` of its initial. The mass of gas remaining is

Options

A. 7.5 g
B. 1.5 g
C. 2.5 g
D. 3.5 g

Answer

A

Explanation

`PV = (10)/(M) RT " "` ….. (1)
Let x g of the gas remain in the flask when find pressure `(P)/(2) , (2T)/(3)`
`therefore ((P)/(2)) V = ((x)/(M)) R((2T)/(3))` …….. (2)
Dividing (1) by (2) `implies 2 = (10)/(x) xx (3)/(2) implies x = (3 xx 10)/(4) = 7.5` g