Which law relates to the diffusion of gases and their molar masses?

The relationship between the diffusion of gases and their molar masses is described by Graham's Law. This law states that the rate of diffusion of a gas is inversely proportional to the square root of its molar mass. In mathematical terms, this can be expressed as:

[

\text{Rate}_1 / \text{Rate}_2 = \sqrt{M_2 / M_1}

]

where ( \text{Rate}_1 ) and ( \text{Rate}_2 ) are the diffusion rates of the two gases, and ( M_1 ) and ( M_2 ) are their respective molar masses. Essentially, lighter gases (with lower molar masses) diffuse faster than heavier gases. This principle can be observed in practical applications, such as how helium (a lighter gas) diffuses faster than carbon dioxide.

Other laws, such as Boyle’s Law, which deals with the relationship between pressure and volume at constant temperature, Charles's Law, which relates volume and temperature at constant pressure, and Dalton’s Law, which pertains to the partial pressures of gases in a mixture, are not directly connected to diffusion in relation to molar mass. Therefore, Graham's Law is the appropriate choice in