Certified Transport Registered Nurse Certification Practice Exam

Which gas law states that volume is proportional to temperature when pressure is constant?

1. Boyle's Law

2. Charles' Law

3. Avogadro's Law

4. Dalton's Law

The correct answer is: Charles' Law

Charles' Law articulates that the volume of a gas is directly proportional to its absolute temperature when pressure is held constant. This relationship highlights the concept that as the temperature of a gas increases, its volume also increases, provided that no pressure changes occur during this process. This law is fundamental in both chemistry and physics and is instrumental in understanding how gases behave under varying thermal conditions. For instance, when heating a sealed container of gas, if the container can expand, the gas will occupy more volume as its temperature rises, demonstrating the proportional relationship between temperature and volume. In contrast, the other laws focus on different relationships: Boyle's Law pertains to the inverse relationship between pressure and volume at constant temperature, Avogadro's Law concerns the volume of gas with the number of moles at constant temperature and pressure, and Dalton's Law addresses the behavior of gases in a mixture, related to partial pressures. Each of these laws serves a unique purpose in gas behavior, but Charles' Law specifically captures the temperature-volume relationship at constant pressure.