Lei de Graham

Graham's Law, also known as the Law of Diffusion of Graham, describes the relationship between the rate of effusion of gases and their molar masses. Effusion is the process by which a gas escapes from a container through a small opening. The law states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass. This means that gases with lower molar masses effuse more rapidly than gases with higher molar masses.

The mathematical formula representing Graham's Law is: rate of effusion ∝ √(1/M), where M is the molar mass of the gas. When comparing two gases, the formula can be expressed as: rate of effusion₁ / rate of effusion₂ = √(M₂/M₁). This equation allows for the calculation of the relative rate of effusion of two gases based on their molar masses.

Graham's Law is useful in various situations, such as in the study of the separation of gas mixtures and in understanding industrial processes that involve the manipulation of gases. For example, in the semiconductor industry, the separation of gases is crucial for the production of high-purity materials.

It is essential to exercise caution when applying Graham's Law, as it assumes ideal conditions, such as constant temperature and pressure, and that gases behave according to the kinetic theory of gases. Real conditions may slightly diverge from these ideals, affecting the accuracy of predictions.