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. `8:9`

Answer

D

Explanation

`PV=nRT=(m)/(M)RT`
`implies PM=pRT`
`(rho_(1))/(rho_(2))=(P_(1)M_(1))/(P_(2)M_(2))=(P_(1)/(P_(2)))xx((M_(1))/(M_(12)))=(4)/(3)xx(2)/(3)=(8)/(9)`
Here `rho_(1)` and `rho_(2)` are the densities of gases in the vessel containing the mixture.