2.1

• Study material presented

  November 1, 2022
• Kinetic particle model


  A model used to describe thermal energy, temperature, and gas pressure
• Thermal energy


  Energy that particles have due to their motion
• Particles are always in motion, which requires energy
• The more thermal energy an object has

  The faster its particles move, and hence the higher the temperature
• The lowest possible temperature is 0 K (–273°C), a.k.a. absolute zero
• Particles have the least energy at absolute zero
• Gas pressure


  Result of particles colliding with the surface of the container, exerting a force over the area of the surface
• Collision with other particles does NOT cause pressure
• Gas pressure increases with higher temperature


  Particles move faster, so they collide with more force and more frequently
• Gas pressure increases with lower volume


  Particles have less space, so they collide more frequently
• For a fixed mass of gas at constant temperature, pV = constant
• Gas compression example

  • A gas with volume of 3 m2 is compressed from 500 Pa to 2 kPa at constant temperature
• p1 = 500 Pa
• V1 = 3 m3
• p2 = 2 kPa
• V2 = 0.75 m3
• Extrapolate


  To extend the line of a graph to find values outside the measured data

  
• From a volume and temperature experiment, we extrapolate the line until V = 0

  
• The temperature at V = 0 is –273°C, which is set to be 0 K (absolute zero)
• TK

  Temperature in Kelvin
• TC

  Temperature in Celsius
• TK = TC + 273


  Conversion from Celsius to Kelvin
• 37°C = 37 + 273 = 310 K