GAS LAWS




Learning Objectives

  1. To understand the principles behind the ideal gas laws
  2. To understand the origin of the ideal gas laws
  3. To execute experiments that prove the laws


Background Information


  • IDEAL GAS EQUATION: PV=nRT
    • o P = pressure of the gas
    • o V = volume of the gas
    • o n = no. of moles of gas (mol)
    • o T =temperature of the gas (kelvin)
    • o R = ideal, or universal, gas constant (8.314 J•K−1•mol−1)

Charles Law

Gay-Lussac's Law

Boyle's Law

  • Law of volumes
  • Jacques Charles found in 1678
  • For an ideal gas at constant pressure, the volume is directly proportional to the absolute temperature (in kelvin).
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  • The absolute temperature of the gas (in kelvin) and k2 (in m3·K−1) is the constant produced.
  • Law of pressure
  • Found by Joseph Louis Gay-Lussac in 1809.
  • The ratio of the volumes of gases consumed or produced in a chemical reaction is equal to the ratio of simple whole numbers.
  • At constant temperature, the product of an ideal gas's pressure and volume is always constant.
  • Published in 1662 by Robert Boyle
  • Capture02.JPG
  • where P is the pressure (Pa), V the volume (m3) of a gas, and k1 (measured in joules) is the constant from this equation
  • This is known as Boyles law which states: the volume of a given mass of gas is inversely proportional to its pressure, if the temperature remains constant.
  • Capture01.JPG

Relevant Experiments

  • §
  • By heating an empty soda can under a steady Bunsen Burner flame, move the soda can into an ice bath immediately.
Electrolysis of Water
  • Using a Hofmann Voltameter as follows:
  • 150px-Hofmann_voltameter_fr.svg.png
  • Electrolyze 200cm3 of deionized water, knowing that the stoichiometric ratio of hydrogen and oxygen is 2:1 in water.
Syringe Datalogger
  • Connecting a syringe to the end of a pressure datalogger, increase the volume of the syringe at a constant rate.