Basic Gas Law Equation

  • Always use Kelvins because absolute temperature and no negative. Zero is an “absolute zero” and means no molecules are moving.

  • There are many choices for units of pressure that can be easily converted with dimensional analysis.

  • STP: Standard Temperature and Pressure. 0 Celcius/273 Kelvin. 1 atm/760 mmHg

  • Boyles Law: P1V1 = P2V2

    • Temperature and the number of moles are constant and there is an inverse/indirect relationship.

  • Charles’ Law: V1/T1 = V2/T2

    • Pressure and moles held constant and there is a direct relationship.

    • Volume will never hit zero, unknown if anything will hit zero Kelvin.

  • Gay-Lussac’s Law: P1/T1 = P2/T2

    • Volume and moles held constant. Pressure and temperature are in a direct relationship.

  • Avogadro's Law: V1/n1 = V2/n2

    • Temperature and pressure held constant. Moles and volume in a direct relationship.

  • Combined Gas Law: P1V1/T1 = P2V2/T2

    • The number of moles are held constant