A gas mixture of equal moles of H 2 and CH 4 is kept in a container fitted with a porous plug. After some time, the gas remaining in the container will be richer in:

CH 4 , because H 2 diffuses out faster leaving CH 4 behind

H 2 , because it diffuses out faster in most cases

Both will remain in equal proportion under typical conditions

Neither, since the mixture cannot separate according to standard textbooks

A gas mixture of equal moles of H 2 and CH 4 is kept in a…

Answer: CH₄, because H₂ diffuses out faster leaving CH₄ behind.

A H₂, because it diffuses out faster in most cases
B CH₄, because H₂ diffuses out faster leaving CH₄ behind
C Both will remain in equal proportion under typical conditions
D Neither, since the mixture cannot separate according to standard textbooks

Correct answer: B. CH₄, because H₂ diffuses out faster leaving CH₄ behind

Explanation: By Graham Law, the lighter gas H₂ effuses out faster through the porous plug, so the container becomes richer in the heavier CH₄.

Graph of pressure versus volume for a fixed amount of gas at constant temperature: the curve falls steeply then flattens, a hyperbola showing pressure inversely proportional to volume.

Boyle's law: at constant temperature the pressure of a fixed mass of gas is inversely proportional to its volume (P ∝ 1/V), so the P–V plot is a hyperbola — halving the volume doubles the pressure. Image: Reginaprice2013, CC BY-SA 3.0, via Wikimedia Commons.

Concept context

Discover why gases expand to fill any container while liquids flow and solids hold their shape. Master the gas laws, the ideal gas equation, and the reasons real gases deviate from ideal behavior.

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A gas mixture of equal moles of H2 and CH4 is kept in a container fitted with a porous plug. After some time, the gas remaining in the container will be richer in:

Concept context

More States of Matter questions

A gas mixture of equal moles of H₂ and CH₄ is kept in a container fitted with a porous plug. After some time, the gas remaining in the container will be richer in: