We will assume that the question is discussing 1.000 atm of Nâ initially. The question is discussing diffusion rates of two gases and asks us to identify the species. We can use Graham's Law to attempt this problem with the following formula:
Rateâ/Rateâ = sqrt(Mâ/Mâ)
We are told that the Nâ is 3.55 times as fast as the unknown species, so rate 1 = 3.55 and rate 2 = 1. We know the molecular weight of Nâ as 28 g/mol. Now we can use the equation above to solve for the molecular weight of the unknown, Mâ:
3.55/1 = sqrt(M2/28)
(3.55)² = Mâ/28
Mâ = 28 (3.55)â
Mâ = 353 g/mol
The unknown compound has a molecular mass of roughly 353 g/mol and this is very close to the molecular mass of UFâ which is 352.02 g/mol. Therefore, it is likely that the unknown gas is UFâ.
