If the four tubes of a car are filled to the same pressure with `N_(2),O_(2) , H_(2)`, and helium separately , then which one will be filled first ?

Options

A. `N_(2)`
B. `O_(2)`
C. `H_(2)`
D. `He`

Answer

C

Explanation

Under identical conditiosn of `T` and `p`, the rates of effusion for gaseous substances are inversely proportional to the square roots of their molar masses:
`r prop (1)/(sqrt(M))`
Lower the molecular mass , faster it wil effuse out and will be filled first. Thus , `H_(2)` gas with the lowest molecular mass is filled first.