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At constant pressure, the volume of a gas is directly proportional to its absolute temperature. This is:

Answer: Charles’s law.

A Boyle’s law
B Charles’s law
C Gay-Lussac’s law
D Graham’s law

Correct answer: B. Charles’s law

Explanation: Charles’s law: at constant pressure, V ∝ T (in kelvin).

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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At constant pressure, the volume of a gas is directly proportional to its absolute temperature. This is:

Concept context

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