Two separate bulbs contain ideal gas `A` and `B`. The density of a gas `A` is twice that of a gas `B`. The molecular mass of `A` is half that of gas `B`. The two gases are at the same temperature. The ratio of the pressure of `A` to that gas `B` is

Options

A. `2`
B. `1//2`
C. `4`
D. `1//4`

Answer

C

Explanation

`d_(a)= 2d_(b), 2M_(a)=M_(b)`
`PV= nRT=(m)/(M)RT, P=(m)/(V).(RT)/(M)=(dRT)/(M)`
`(P_(a))/(P_(b))=(d_(a))/(d_(b))(M_(b))/(M_(a))=(2d_(b))/(d_(b))xx(2M_(A))/(M_(a))=4`