Physics P6

• What happens to the pressure of a gas when its volume is decreased at constant temperature?

  The pressure increases
• Why does pressure increase when the volume of a gas is decreased?

  Particles travel shorter distances between impacts
• What happens to the number of impacts per second when the volume of a gas is decreased?

  The number of impacts per second increases
• If the volume of a gas is halved, what happens to the pressure?

  The pressure is doubled
• What occurs to the pressure of a gas when its volume is increased?

  The pressure decreases
• Why does pressure decrease when the volume of a gas is increased?

  Particles travel greater distances between impacts
• What is the relationship between pressure and volume of a gas at constant temperature?

  Pressure is inversely proportional to volume
• What is the equation linking pressure and volume of a gas?

  p × V = constant
• How can you rearrange the equation p × V = constant to find pressure?

  p = constant / V
• How can you rearrange the equation p × V = constant to find volume?

  V = constant / p
• What happens to the internal energy of a substance when it is heated?

  It increases
• What is internal energy?

  Sum of kinetic and potential energy of particles
• What do the flat horizontal sections of a temperature change graph indicate?

  The substance is changing state
• What is latent heat?

  Energy transferred during a change of state
• What is specific latent heat?

  Energy required to change 1 kg without temperature change
• What is specific latent heat of fusion?

  Energy required to melt 1 kg without temperature change
• What is specific latent heat of vaporisation?

  Energy required to evaporate 1 kg without temperature change
• How can you calculate the energy needed to change the state of a substance?

  E = m × l
• What is the formula for density?

  Density = mass / volume
• How does temperature relate to the average kinetic energy of gas particles?

  Temperature is related to average kinetic energy
• What happens to gas particles when the gas is heated?

  They gain kinetic energy and move faster
• What can happen to the temperature of a gas when it is compressed quickly?

  The temperature can rise
• Why does the temperature of a gas rise when compressed quickly?

  Work is done on the gas, increasing energy
• What causes gas pressure on a surface?

  Force of gas particles hitting the surface
• What happens to gas pressure when the temperature in a sealed container is increased?

  The pressure increases
• Why does pressure increase when the temperature of a gas is increased?

  Particles move faster and hit surfaces harder
• What are the properties of gases?

  • Low density
  • No fixed volume or shape
  • Can be compressed and flow
  • Spread out to fill all available space
• What are the properties of liquids?

  • Usually lower density than solids
  • Fixed volume
  • Shape is not fixed, can flow
• What are the properties of solids?

  • High density
  • Fixed volume
  • Fixed shape (unless deformed)
• What are the key terms related to changes of state?

  • Boiling
  • Condensation
  • Conservation of mass
  • Density
  • Evaporation
  • Freezing
  • Fusion
  • Internal energy
  • Latent heat
  • Melting
  • Specific latent heat
  • Sublimation
  • Vaporisation
• What is the conservation of mass in changes of state?

  • Mass remains constant
  • Number of particles does not change
  • No new substances are produced
• How does kinetic energy change with temperature increase?

  Kinetic energy of particles increases
• How do you calculate density?

  Density = mass / volume
• What happens to the kinetic energy store of particles when temperature increases?

  It increases and particles move faster
• What is the relationship between mass and volume in calculating density?

  Density is mass divided by volume
• What is the significance of the latent heat in phase changes?

  It does not change temperature but changes internal energy
• What can happen if the kinetic energy of a substance's particles changes significantly?

  The substance may change state
• What is the effect of heating on the internal energy of a substance?

  Heating increases internal energy
• What is the relationship between temperature and pressure in gases?

  Temperature increase leads to pressure increase
• What happens to gas particles when they collide with container walls?

  They exert pressure on the walls