If 100cm3 of oxygen diffuses through a porous plug at 5cm3/sec how long will it take 200cm3 of methane to diffuse through the same plug under similar conditions

Answer 1

rate1 = oxygen at 5 cc/sec
rate 2 = methane at x cc/sec
molar mass = mm oxygen = 32
molar mass = mm methane = 16
(rate1/rate2) = sqrt [(mm CH4/mm O2)]
(5/x)= sqrt (16/32).
25/x^2 = 16/32 = 0.5
25 = 0.5x^2
x = sqrt(25/0.5) = sqrt (50) = 7.07
so rate CH4 = 7.07 cc/sec
It takes 1 sec to diffuse 7.07 cc so it will take ? sec to diffuse 200 cc