Chemistry Kinetic Theory and Gas Law

Kinetic Molecular Theory

• Describes that ALL matter is in constant, random motion

  • Gases consist of tiny particles

  • Particles are in constant motion

    • moving rapidly in straight lines in all directions and have kinetic energy

  • Collisions between gas particles OR particles and container walls are elastic

    • NO loss in kinetic energy

  • No force of attraction or repulsion between gas particles

  • Average KE particles are directly proportional to kelvin temp

Ideal Gases

• Follow all 5 assumptions of the kinetic theory at all times

  • Assume they exist during calculations

*NO SUCH THING…ALL gases are REAL*

Gas Properties

• Mass, even though the particles are small

• Can be compressed

  • Increased pressure = decreased volume

• Fluidity - particles have low attraction so are able to flow

• Expansion - Gases fill their containers completely (up to 1000x their size)

• Diffusion - Spread out uniformly without aide of air movement

Moles

• How many molecules of gas are there

Temperature

• How fast the molecules are moving

  • K = C+273

  • C = K-273

Volume

• How big a space of molecules of a gas take up

• 1 mL = 1cm³

Pressure

• How often the molecules are hitting each other OR the side of a containe

Combined Gas Law

• Is more realistic: all 3 factors affect each other as they change