In Charles' Law, which variable is held constant?

In Charles' Law, which variable is held constant?

• A. Pressure
• B. Volume
• C. Temperature
• D. Mass

Answer: (A)

Charles' Law describes how the volume of a gas changes with temperature when the pressure stays the same. Because the relationship is defined at constant pressure, pressure is the variable that does not change. As temperature (in Kelvin) increases, the volume increases to keep the pressure constant, so volume is directly proportional to temperature under this condition. The usual form is V/T = constant when P is constant. Mass (amount of gas) is assumed fixed in these scenarios, and temperature and volume are the variables that actually change.

Charles' Law describes how the volume of a gas changes with temperature when the pressure stays the same. Because the relationship is defined at constant pressure, pressure is the variable that does not change. As temperature (in Kelvin) increases, the volume increases to keep the pressure constant, so volume is directly proportional to temperature under this condition. The usual form is V/T = constant when P is constant. Mass (amount of gas) is assumed fixed in these scenarios, and temperature and volume are the variables that actually change.