Which law relates pressure and volume for a gas at constant temperature?

Which law relates pressure and volume for a gas at constant temperature?

• A. Pascal's Law
• B. Boyle's Law
• C. Charles' Law
• D. Avogadro's Law

Answer: (B)

Pressure and volume of a gas at constant temperature move in opposite directions; as you compress the gas to a smaller volume, its pressure rises to keep the temperature the same. This inverse relationship is Boyle's law, which can be written as P1V1 = P2V2, meaning the product of pressure and volume stays constant when temperature and the amount of gas don’t change. A practical takeaway is that halving the volume doubles the pressure, assuming temperature is constant. This principle is useful for understanding how pistons, syringes, or breathing work, where volume changes inside a container without a temperature change. Other laws describe different situations (for example, pressure transmission in fluids, volume changes with temperature, or volume changes with amount of gas), but the specific scenario asked—pressure changing with volume at constant temperature—follows Boyle's law.

Pressure and volume of a gas at constant temperature move in opposite directions; as you compress the gas to a smaller volume, its pressure rises to keep the temperature the same. This inverse relationship is Boyle's law, which can be written as P1V1 = P2V2, meaning the product of pressure and volume stays constant when temperature and the amount of gas don’t change. A practical takeaway is that halving the volume doubles the pressure, assuming temperature is constant. This principle is useful for understanding how pistons, syringes, or breathing work, where volume changes inside a container without a temperature change. Other laws describe different situations (for example, pressure transmission in fluids, volume changes with temperature, or volume changes with amount of gas), but the specific scenario asked—pressure changing with volume at constant temperature—follows Boyle's law.