Pressure of 1 g of an ideal gas A at `27^(@)C` is found to be 2 bar, when 2 g of another gas B is introduced in the same flask at same temperature. The pressure becomes 3 bar. Find a relationship between their molecular masses.

Options

A. `M_(A) = 4 M_(B)`
B. `M_(B) = 4 M_(A)`
C. `M_(A) = 2 M_(B)`
D. `M_(B) = 2 M_(A)`

Answer

B

Explanation

`P_(A) = 2` bar `T_("Total") = P_(A) + P_(B)`
PV = nRT
`P_("Total") = 3` bar `P_(B) = 3.2 = 1` bar
PV = W/M RT
`(P_(A) M_(A))/(W_(A)) = (P_(B) M_(B))/(W_(B)) or (2 xx M_(A))/(1) xx (1 xx M_(B))/(2)`
or `(M_(A))/(M_(B)) = (1)/(4)` or `M_(B) = 4 M_(A)`