Estimating Diffusivity of Freon using known Diffusivity of Methane

[lewdtenant]

How can I estimate the diffusivity of a compound such as CCl2F2 (freon-12) using the known diffusivity of methane?

I would like to estimate it for both air and water. I have a diffusivity value of methane for each medium.

Any advice/help is much appreciated.

 

[lewdtenant]

Ok so I figured it out, after an extensive google search.

You have to use Graham's law, which states:

Rate1/Rate2 = (M2/M1)^1/2

M = Molecular Weight

(For anyone that cares)

 

[ravenprp]

To estimate the diffusivity of CCl2F2 (freon-12) using the known diffusivity of methane, you can use the concept of molecular weight and the Kinetic Theory of Gases. The diffusivity of a gas is inversely proportional to its molecular weight, meaning that a lighter gas will diffuse faster than a heavier gas in the same medium.

First, you can calculate the molecular weight of methane (CH4) and CCl2F2 (freon-12) using the periodic table. The molecular weight of methane is 16 g/mol, and the molecular weight of CCl2F2 is 120 g/mol.

Next, you can use the following formula to estimate the diffusivity of CCl2F2 in air and water:

Diffusivity of CCl2F2 = (Molecular weight of methane / Molecular weight of CCl2F2) * Diffusivity of methane

For example, if the diffusivity of methane in air is 0.2 cm^2/s, the estimated diffusivity of CCl2F2 in air would be:

Diffusivity of CCl2F2 = (16 g/mol / 120 g/mol) * 0.2 cm^2/s = 0.0267 cm^2/s

Similarly, for water, if the diffusivity of methane is 0.1 cm^2/s, the estimated diffusivity of CCl2F2 in water would be:

Diffusivity of CCl2F2 = (16 g/mol / 120 g/mol) * 0.1 cm^2/s = 0.0133 cm^2/s

Please note that these are only estimated values and may not be completely accurate. Other factors such as temperature and pressure can also affect the diffusivity of a gas. It is always recommended to conduct experiments to determine the actual diffusivity of a compound in a specific medium.