SCIENCE M1

• Boyle's study

  1. Varied pressure and observed effect on gas volume

  2. Did not change temperature

  
• Boyle noticed that the volume of the gas decreased as the pressure exerted on it increased
• Syringes

  • Utilize Boyle's law on a very basic level
• Gases

  Take the shape of the container wherein particles are able to move naturally to all parts of the container
• Particles of gases

  • Move at random directions very fast travelling in straight-line paths
  • The molecules of the gas are very large compared to the very short distances between them
• Boyle's Law

  Relationship between the volume of a gas and its pressure, without changing its temperature

  
• Boyle varied the pressure and noticed its effect on the volume of the gas

  
• The volume of the gas decreased as the pressure exerted on it increased
• Syringes of all types utilize Boyle's law on a very basic level
• Increasing pressure

  Decreases the size (volume) of the marshmallow
• Decreasing pressure

  Increases the size (volume) of the marshmallow
• Kinetic Molecular Theory

  Can be employed to explain Boyle's conclusion
• The molecules of a gas exert pressure on the walls of its container
• The molecules move nearer to one another when pressure is applied on the gas resulting in the decrease in volume
• This increases the chances of collision among the molecules and the walls of the container; thus, pressure is increased
• Pressure


  The force exerted by the gas on the walls of its container divided by the surface area of the container
• Common units of pressure

  • Pascal (Pa)
  • Atmosphere (atm)
  • Torr
  • Millimeter mercury (mm Hg)
• Volume


  The space occupied. The volume of the gas is equal to the volume of the vessel or container
• Common units of volume

  • Cubic meter (m3)
  • Cubic centimeter (cm3)
  • Liter (L)
  • Milliliter (mL)
• Temperature

  The degree of hotness or coldness
• Units of temperature


  • Degree Celsius (°C)
  • Degree Fahrenheit (°F)
  • Kelvin (K)
• Standard temperature and pressure (STP)

  Standard temperature is 0 °C or 273.15 K and the standard pressure is 1 atm pressure
• At STP, one mole of gas occupies 22.4 L of volume
• 1 atm = 760 torr = 760 mm Hg
• 1 torr = 1 mm Hg
• 1 atm = 101,325 Pa
• 1 atm = 76 cm Hg
• Standard pressure is 1 atm
• Standard temperature is 0 °C or 273.15 K
• Volume of one mole of a gas at STP is 22.4 L
• Pressure and volume of a gas

  Inverse relationship

  
• PV = k, where k is a constant for a given sample of gas and depends only on the mass of the gas and the temperature</b>

  
• Increasing pressure

  Decreases the volume of the gas
• Decreasing pressure

  Increases the volume of the gas
• Volumes

  • 18 m3
  • 29 m3
  • 0.034 m3
  • 55 m3
• Gas particles


  Have a very weak intermolecular force of attraction, hence they move as far as possible from each other. They have the tendency to occupy all the spaces they are contained in.
• If the pressure is increased


  The volume will be decreased forcing the gas particles to move closer to one another
• Volume of a gas


  Is inversely proportional to its pressure, if temperature and amount of gas are held constant

  
• This was stated by

  Robert Boyle
• Volume

  The force exerted by the gas on the walls of its container divided by the surface area of the container