The density of gas A is twice that to B at the same temperature. The molecular weight of gas B is twice that of A. The ratio of pressure of gas A and B will be :

Options

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

Answer

C

Explanation

`d_(A) = 2d_(B) , 2M_(A) = M_(B), PM = dRT`
`(P_(A))/(P_(B)) xx (M_(A))/(M_(B)) = (d_(A))/(d_(B)) xx (RT)/(RT) rArr (P_(A))/(P_(B)) xx (1)/(2) = 2 rArr (P_(A))/(P__(B)) = (4)/(1)`