A sample of N₂ gas is contaminated with a gas (gas A) of unknown molar mass. The partial pressure of each gas is known to be 200. torr at 25°C. The gases are allowed to effuse through a pinhole, and it is found that gas A escapes at 2.65 times the rate of N₂. The molar mass of gas A is

Question

Quizplus · Accepted Answer

Graham's law of effusion states that the rate of effusion of a gas is inversely proportional to the square root of its molar mass. Therefore, the molar mass of gas A is 2.65^2 = 7.02 times less than that of N2. The molar mass of N2 is 28 g/mol, so the molar mass of gas A is 28 g/mol / 7.02 = 3.99 g/mol.

A Sample of N2 Gas Is Contaminated with a Gas

A Sample of N₂ Gas Is Contaminated with a Gas