Charles’s law

Definition

Charles's law states that the volume of a gas is directly proportional to its temperature when pressure and the amount of gas are held constant. Mathematically, it is expressed as $V \propto T$ or $\frac{V_1}{T_1} = \frac{V_2}{T_2}$.

5 Must Know Facts For Your Next Test

1. Charles's law requires temperature to be in Kelvin for accurate calculations.
2. The relationship described by Charles's law means that if the temperature of a gas increases, its volume increases proportionally.
3. Charles's law can be derived from the Ideal Gas Law by holding pressure and amount (moles) constant.
4. Real gases follow Charles's law closely at high temperatures and low pressures.
5. Graphically, Charles's law is represented as a straight line when plotting volume against temperature.

Review Questions

• What must remain constant for Charles's law to apply?
• How does the volume of a gas change if its temperature is doubled according to Charles’s law?
• Why must temperature be measured in Kelvin when using Charles’s law?

Related terms

Boyle’s Law: Boyle’s Law states that the volume of a gas is inversely proportional to its pressure when temperature and amount are held constant.

Ideal Gas Law:

The Ideal Gas Law combines Boyle’s, Charles’s, and Avogadro’s laws into one equation: $PV = nRT$.

Kelvin Scale: The Kelvin scale is an absolute temperature scale starting at absolute zero, used in gas laws for accurate thermal measurements.