In a pressure vs. volume experiment involving a gas, which method is typically used to control the volume of the gas?

• A. Changing the temperature of the gas
• B. Adjusting the position of a movable piston in a sealed container
• C. Adding more gas to the container
• D. Altering the type of gas used in the experiment

Answer: (B)

Verified step by step guidance

1. Understand the context: In a pressure vs. volume experiment, the goal is to observe how pressure changes as volume changes for a gas sample, typically at constant temperature (isothermal conditions).
2. Recall that volume control means physically changing the space the gas occupies without changing the amount of gas or its temperature.
3. Consider the options: Changing temperature affects gas behavior but does not directly control volume; adding more gas changes the amount of gas, not volume; altering the gas type changes gas properties but not volume.
4. Recognize that adjusting the position of a movable piston in a sealed container directly changes the volume available to the gas by compressing or expanding the space it occupies.
5. Conclude that the typical method to control volume in such experiments is by moving the piston, which allows precise and direct volume adjustments while keeping other variables constant.