Methane gas,CH₄,effuses through a barrier at a rate of 0.568 mL/minute.If an unknown gas effuses through the same barrier at a rate of 0.343 mL/minute,what is the molar mass of the gas? A) 20.8 g/mol B) 28.0 g/mol C) 32.0 g/mol D) 44.0 g/mol E) 64.0 g/mol

Question

Quizplus · Accepted Answer

According to Graham's law of effusion, the rate of effusion of a gas is inversely proportional to the square root of its molar mass.

Let's set up an equation using this law:

(rate of methane gas effusion) / (rate of unknown gas effusion) = sqrt(molar mass of unknown gas) / sqrt(molar mass of methane gas)

(0.568 mL/min) / (0.343 mL/min) = sqrt(molar mass of unknown gas) / sqrt(16.04 g/mol)

1.654 = sqrt(molar mass of unknown gas) / 4.004

6.624 = molar mass of unknown gas

Therefore, the molar mass of the unknown gas is 44.0 g/mol (choice D).

Methane Gas,CH4,effuses Through a Barrier at a Rate of 0

Methane Gas,CH₄,effuses Through a Barrier at a Rate of 0