Gas Laws

Boyle’s Law

the volume of a given mass of gas varies inversely with the pressure when the temperature is kept constant

We use P1 and V1 to stand for the initial pressure and initial volume of a gas. After a change has been made, P2 and V2 stand for the final pressure and volume. The mathematical relationship of Boyle's Law becomes:

P 1 × V 1 = P 2 × V 2

  • 2 changing variables - pressure + volume

  • constant variable - temperature

  • inverse relationship

  • real life example: syringe with marshmallow inside

Why is Boyle's law graph curved? | SocraticCharles’s Law

the volume of a given mass of gas varies directly with the temperature of the gas when the pressure is kept constant

We will use V1 and T1 to stand for the initial volume and temperature of a gas, while V2 and T2 stand for the final volume and temperature. The mathematical relationship of Charles's Law becomes:

  • 2 changing variables - temperature + volume

  • constant variable - pressure

  • direct relationship

  • real life example: tire cold in the winter (temperature decreases) ➡ pressure decreases

Gay-Lussac’s Law

the temperature of gas varies directly with the pressure when the volume is kept constant

We will use V1 , P1, and T1 to stand for the initial volume, pressure, and temperature of a gas, while V2, P2, and T2 stand for the final volume, pressure, and temperature. The mathematical relationship of Charles's Law becomes:

  • 2 changing variables - pressure + temperature

  • constant variable - volume

  • direct relationship

  • real life example: rice cooker gets heated up (temperature increases), and pressure increases inside of the cooker; this causes the whistle to blow