Question

If 100cm3 of oxygen diffused in 4 seconds and 50cm3 of gas Y diffused in 3 seconds,calculate the relative molecular mass of gas Y (o=16).

Answer 1

rate oxygen = 100/4 = 25 cc/sec

rate gas Y = 50 cc/3 sec = 16.67 cc/sec
mm stands for molar mass
rate O2/rate Y = sqrt (mm Y/mm O2)
(25/16.67) = sqrt (mm Y/32)
Solve for mm Y
Post your work if you get stuck.