The Nature of gases Section 10.1

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The Nature of gasesSection 10.1

• After reading Section 10.1, you should know
• the three assumptions of the kinetic theory
• how to convert pressure readings between atm,
  kPa and mm Hg
• how the kinetic theory affects gas pressure

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Kinetic Theory

• Atoms are in constant motion
• 3 Assumptions of the Kinetic Theory for gases
• No attractive or repulsive forces exist between
  gas particles
• The particles in a gas are in constant, random
  motion
• All collisions are perfectly elastic
• kinetic energy is transferred from one particle
  to the next without losing any energy

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Gas Pressure

• The force exerted by a gas per unit of surface
  area
• A vacuum exists if there is no gas particles or
  pressure
• 1 atm 760 mm Hg 101.3 kPa

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Gas Pressure

• Atmospheric Pressure force exerted from
  collisions of air particles with objects
• Measured with a barometer

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Kinetic Energy and Kelvin Temperature

• Particles absorb energy, which causes them to
  move faster
• This increase in kinetic energy causes the
  temperature to rise
• At absolute zero (0 Kelvin) the molecules have no
  kinetic energy and are no longer moving
• Kinetic energy and Kelvin temperature are
  directly related

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After reading Section 10.1, you should know

• the three assumptions of the kinetic theory
• how to convert pressure readings between atm,
  kPa and mm Hg
• how the kinetic theory affects gas pressure