3.3 Particle Model & Pressure

• What is the state of molecules in a gas according to the kinetic theory?

  Molecules are in constant random motion
• How is the temperature of a gas related to its molecules?

  It relates to the average kinetic energy
• What happens to the average kinetic energy of a gas as its temperature increases?

  The average kinetic energy increases
• What does random motion of gas molecules imply?

  Molecules travel in no specific path
• What is Brownian motion?

  Random motion of tiny particles in a fluid
• How does the motion of gas molecules change with temperature and pressure?

  It changes according to temperature and pressure
• What happens to the average speed of gas molecules as temperature increases?

  The average speed of the molecules increases
• What happens to the kinetic energy of gas molecules if the volume remains constant?

  Kinetic energy increases with speed
• How is pressure defined in a gas?

  Force exerted per unit area

  
• What occurs when gas molecules collide with the walls of their container?

  They exert pressure on the walls

  
• What happens to pressure when gas is heated at constant volume?

  Pressure increases due to more collisions

  
• How does an increase in temperature affect gas pressure at constant volume?

  It increases the pressure due to more collisions

  
• What is the relationship between pressure and volume in a gas at constant temperature?

  • Pressure increases when volume decreases (compression)
  • Pressure decreases when volume increases (expansion)

  
• What happens to the pressure of a gas when it is compressed?

  Pressure increases
• How does compressing a gas affect the frequency of collisions with container walls?

  It increases the frequency of collisions

  
• What is the effect of changing pressure on a gas at constant temperature?

  It compresses or expands the gas
• What is the equation relating pressure and volume for a fixed mass of gas at constant temperature?

  $pV =$$\text{constant}$

  
• What does Boyle's Law state about pressure and volume?

  Pressure and volume are inversely proportional
• If the volume of a gas decreases, what happens to its pressure?

  Pressure increases
• What happens to gas particles when volume decreases?

  They collide more frequently with walls

  
• What is the key assumption of Boyle's Law?

  Temperature and mass remain constant
• What happens to the temperature of a gas when work is done on it?

  The temperature increases
• How does compressing a gas affect its internal energy?

  It increases the internal energy
• What is an example of doing work on a gas?

  Using a bicycle pump
• What happens when gas expands and does work?

  It loses energy and cools down
• What occurs when pressurized carbon dioxide is released from a cylinder?

  It loses energy and can freeze
• What are the effects of work done on a gas versus work done by a gas?

  • Work done on a gas: temperature rises
  • Work done by a gas: temperature falls