A sample of oxygen gas (O₂)was found to effuse at a rate equal to three times that of an unknown gas.The molecular weight of the unknown gas is ________ g/mol. A)288 B)96 C)55 D)4 E)10.7

Question

Quizplus · Accepted Answer

The rate of effusion of a gas is inversely proportional to the square root of its molar mass, according to Graham's law of effusion. If oxygen gas (molecular weight = 32 g/mol) effuses at a rate three times that of the unknown gas, then the ratio of their rates (rate of O2/rate of unknown gas) is 3:1. According to Graham's law, (rate of O2/rate of unknown gas) = sqrt(Molar mass of unknown gas/Molar mass of O2). Squaring both sides gives (3)^2 = Molar mass of unknown gas / 32. Solving for the molar mass of the unknown gas gives 288 g/mol.

A Sample of Oxygen Gas (O2)was Found to Effuse at a Rate

A Sample of Oxygen Gas (O₂)was Found to Effuse at a Rate