Consider the following: CH4, SiH3Cl, Ar, and CH2F2.

Question

(a) Which one will diffuse the fastest?
(b) What is the rms speed (m/s) of the slowest-moving atom or molecule at 25°C?

Answer 1

a)
The fastest diffuser is the loest molar mass substance.

b)
urms = sqrt(3RT/M)
M is molar mass. R is 8.314. T in kelvin.