A and B are ideal gases. The molecular weights of A and B are in the ratio of `1 : 4`. The pressure of a gas mixture containing equal weights of A and B is P atm. What is the partial pressure (in atm.) of B in the mixture

Options

A. `(P)/(5)`
B. `(P)/(2)`
C. `(P)/(2.5)`
D. `(3P)/(4)`

Answer

A

Explanation

`M_(a)=a` and `M_(B)=4a`
`w_(A) = w_(B)=m(`say)
`x_(B)=(m//4a)/(4//ma+m//a)=(1)/(5)`