A gaseous mixture contains oxygen and nitrogen in the ratio of `1 : 4` by weight therefore the ratio of their number of molecules is

Explanation

Let wt. of given mixture = Wg
Amount of `O_(2)` in mixture `=(W xx 1)/5 = (4W)/5g`
Moles of `O_(2) = W/(5 xx 32)`
Molecules of `O_(2) = W/(5 xx 32) xx 6.022 xx 10^(23)`
Moles of `N_(2) =(4W)/(5 xx 28)`
Molecules of `N_(2) = (4W)/(5 xx 28) xx 6.022 xx 10^(23)`
Ratio of molecules of `O_(2)` and `N_(2)`
`W/(5 xx 32) xx 6.022 xx 10^(23) : (4W)/(5 xx 28) xx 6.022 xx 10^(23)`
`1/32 : 1/7`
7 : 32