A certain volume of mass A recquired 120 seconds to diffuse out.An equal volume of oxygen recquired 85 seconds to diffuse out under the same conditions.what is the relative molecular mass?

Answer 1

Use Graham's Law of Effusion => SqrRt(M-A)/t-A = SqrRt(M-B)/t-B
SqrRt(O2)/t(O2) = SqrRt(M-B)/t(B)
=> M-B = 63.8 amu