Gas Laws

Syllabus tag: KCSE | Chemistry | Form 3 | Topic 12 Gas Laws

Lesson objectives

By the end of this topic, you should be able to:

• State and apply Boyle's law, Charles' law and the combined gas equation.
• Convert temperatures to the kelvin scale and work at s.t.p.
• State and apply Graham's law of diffusion.
• Explain the gas laws using the kinetic theory.

Summary

Boyle's law — at constant temperature:

PV = constant

Charles' law — at constant pressure, with T in kelvin:

V ÷ T = constant

Combined gas law:

P₁V₁ ÷ T₁ = P₂V₂ ÷ T₂

Graham's law — the rate of diffusion is inversely proportional to the square root of the density, or of the molar mass.