A 100 meter hollow tube of uniform thickness has two open ends X and Y. Ammonia gas is sent into the tube from end X and hydrogen chloride from end Y, simultaneously. At what distance from end 'X', the gases first meet to form a smoke ring?

Explanation

Two gases diffuse into the pipe from their respective ends, X and Y and meet at a point .O

Using Graham.s law,` (r_1)/(r_2) = sqrt((M_2)/(m_1)) =sqrt((36.5 )/(17 ))=1.47`
The ratio of rate of diffusion interms of distance
`(1.47)/(1) =(l)/(100- l) ` (or) `l=59.5` (from end X)