What does Graham's Law of Effusion state?

Graham's Law of Effusion states that the rate at which gas molecules effuse is inversely proportional to the square root of their molar mass (or density). This implies that lighter gases, those with a lower molar mass, effuse more quickly than heavier gases. The principle behind this is that gas molecules move randomly and at different speeds, with lighter molecules hitting the effusion opening and escaping more frequently than heavier ones, leading to a greater effusion rate.

This relationship can be expressed mathematically as:

[

\frac{Rate_1}{Rate_2} = \sqrt{\frac{M_2}{M_1}}

]

where (Rate_1) and (Rate_2) are the rates of effusion of two different gases, and (M_1) and (M_2) are their respective molar masses. This explains why the correct answer focuses on the inverse relationship to the square root of gas density.

In the context of the other options, while temperature and pressure can influence gas behavior, they do not specifically describe Graham's Law of Effusion. Effusion is more about the properties of the gas molecules themselves (their mass/density) rather than external