How to calculate the rate of diffusion based on different level of concentration?

For a gas, the rate at which diffusion occurs is proportional to the square root of the density of the gas. The density of a gas is equal to the mass of the gas divided by the volume of the gas. If the volume is held constant one gas is compared with another with another,

\(\frac{R_2}{R_1}=\sqrt{\frac{M_1}{M_2}}\)

where R is the rate of diffusion in mol/s and M is the molar mass in g/mol. This is known as Graham's law of diffusion.

So if you want to answer your question, plug-in different values into this formula to see what happens.

For example:

Compare the rate of diffusion between fluorine and chlorine gases. Fluorine gas, F2, has a molecular mass of 32 grams. Chlorine gas, Cl2, has a molecular mass of 70.90 grams.

\(\frac{R_2}{R_1}=\sqrt{\frac{_{70.9\ g}}{32\ g}}=1.49\)

Therefore, fluorine gas is 1.49 times as fast as chlorine gas.