LAW OF CONSERVATION OF MASS

• Gases


  • Easy to compress
  • Expand to fill their containers
  • Occupy far more space than the liquids or solids from which they form
• Gases


  • Molecules move independently from each other
  • Most are colorless
  • Flammable like hydrogen
• Gas particles


  Spread about or diffuse to fill all the space in any container
• Gases


  • Have very low density and viscosity
  • Cannot be directly seen as they are colorless
• Commonly used units for volume


  • Cubic meter
  • Cubic decimeter
  • Cubic centimeter
  • Liter
  • Milliliter
  • Quart
  • Gallon
• • 1 milliliter is equal to 1 cubic centimeter
  • 1 liter is equal to 1 cubic decimeter
  • 1 cubic meter is equal to 1000 liters
• Converting volume units


  • 350 liters = 0.35 cubic meters
  • 935 milliliters = 935 cubic centimeters
• Commonly used units for pressure

  • Pascal
  • Atmosphere
  • Millimeters of mercury
  • Centimeters of mercury
  • Torr
  • Pound per square inch
• 1 atmosphere = 760 millimeters of mercury = 76 centimeters of mercury = 760 torr = 101,325 pascals = 14.6956 pounds per square inch
• Converting pressure units


  • 6.0 torr = 800 pascals
  • 2.0 kilopascals = 0.02 atmospheres
• Temperature units and equivalents

  • Degrees Celsius
  • Kelvin
  • Degrees Fahrenheit
• 0 degrees Celsius = 273.15 Kelvin

  0 degrees Celsius = 32 degrees Fahrenheit
• Converting temperature units


  • 38 degrees Celsius = 311.15 Kelvin

  40 degrees Fahrenheit = 4 degrees Celsius
• Standard temperature and pressure (STP)

  1.0 atmosphere pressure and 0 degrees Celsius temperature

  1 mole of gas occupies 22.4 liters at STP
• Kinetic molecular theory of gases

  • Volume of gas particles is negligible compared to volume of gas

  Gas particles exert no attractive forces on each other or surroundings

  Gas particles are in constant random motion and collide elastically

  Average kinetic energy of gas molecules is directly proportional to absolute temperature
• Kinetic molecular theory can explain gas laws like Boyle's law and Charles' law