Two non-reactive monoatomic ideal gases have their atomic masses in the ratio `2:3`. The ratio of their partial pressures, when enclosed in a vessel kept at a constant temperature, is `4:3`. The ratio of their densities is

Options

A. `1:4`
B. `1:2`
C. `6:9`
D. `6:9`

Answer

D

Explanation

`PV = nRT = m/M RT" "rArr" "PM = rho RT`
` rho_1/rho_2 = (P_1 M_1)/(P_2 M_2) = (P_1/P_2) xx(M_1/M_2) = 4/3 xx2/3 = 8/9`
Here `rho_1` and `rho_2` are the densities of gases in the vessel containing the mixture.