Answer: The finite volume of gas molecules becomes significant compared to total volume.
- A Molecules generally move faster as the pressure on the gas increases overall
- B The finite volume of gas molecules becomes significant compared to total volume
- C The temperature of the gas automatically falls as pressure is increased in most cases
- D Intermolecular attractive forces disappear largely once pressure becomes high
Correct answer: B. The finite volume of gas molecules becomes significant compared to total volume
Explanation: At high pressure, gas molecules are compressed close together, so their own volume is no longer negligible compared to the container 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.