Charles's law

Science

Definition

Charles's law states that the volume of a gas is directly proportional to its absolute temperature when pressure and the amount of gas are held constant. Heating a gas causes it to expand; cooling causes it to contract.

Examples

  • A hot-air balloon rises because heating the air inside increases its volume and decreases its density
  • A basketball left outside in winter appears deflated because the cold air inside contracts
  • Bread dough rises faster in a warm oven as gas bubbles inside expand
Key Fact

V₁/T₁ = V₂/T₂ (temperature must be in Kelvin)

Related Terms

Boyle's law Ideal gas law Phases of matter

Study This Concept

Practice Charles's law with free review games in these units:

Chemistry Unit 6: States of Matter and Gas Laws