In an experiment,argon is allowed to effuse through a tiny opening into an evacuated 5.00 × 10² mL flask for 30.0 seconds,at which point the pressure in the flask is found to be 15.0 mm Hg.The experiment is repeated using an unknown gas at the same temperature and pressure.After 30.0 seconds,the pressure is found to be 47.4 mm Hg.What is the molar mass of the gas?

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 the unknown gas is:(Molar mass of argon) x (Pressure of argon / Pressure of unknown gas) x (Time for argon / Time for unknown gas)^2= (39.95 g/mol) x (15.0 mm Hg / 47.4 mm Hg) x (30.0 s / 30.0 s)^2= 4.00 g/mol

In an Experiment,argon Is Allowed to Effuse Through a Tiny