Thermal Physics

• Specific Heat Capacity: The energy required to raise the temperature of 1kg of a given substance by 1 degree Kelvin
• Units of Specific Heat Capacity


  Jkg^-1K^-1
• Specific Latent Heat: The energy required to change the state of 1kg of a substance without a change in temperature
• Specific latent heat of fusion: The transition between a solid and a liquid
• Specific latent heat of vaporisation: The transition between liquid and gas
• Units of Specific Latent Heat

  Jkg^-1
• How does a change in state happen? There must be a transfer of energy in order for bonds to be broken or created
• How does a change in temperature happen? There is an increase or decrease of energy being transferred
• Internal energy


  Kinetic energy + Potential energy
• Celsius to Kelvin


  +273
• -273 degrees


  0K
• Absolute zero: The temperature at which particles have zero kinetic energy
• Assumptions in Kinetic theory: The motion of molecules is...: Random
• Assumptions in Kinetic theory: Collisions between molecules are...

  elastic
• Assumptions in Kinetic theory: The time taken for a collision is...: Negligible compared to the time between collisions
• Assumptions in Kinetic theory: Molecules move in...: Straight lines at a constant speed
• Assumptions in Kinetic theory: All particles are...: Identical (same mass/volume)
• Assumptions in Kinetic theory: Intermolecular forces are...: Negligible (except during collisions)
• Boyle's Law


  Volume is inversely proportional to Pressure, when temperature is kept constant
• Boyle's Law: As the volume decreases...: The particles become closer together and increases the rate of collisions
• Boyle's Law: An increase in rate of collisions leads to...: An increased rate of change of momentum
• Boyle's Law: increased rate of change of momentum means...: The force on the container walls, and so the pressure, increases`
• Charles' Law


  Temperature is directly proportional to volume
• Charles' Law: As temperature increases...

  Average kinetic energy increases
• Charles' Law: Since pressure is constant...: The rate of change of momentum must remain constant
• Charles' Law: To achieve the constant rate of change of momentum...: The rate of collisions will be constant and particles become more separated, increasing the volume
• Pressure Law


  Temperature is directly proportional to pressure
• What is internal energy?

  The sum of potential and kinetic energies
• How can you increase the thermal energy of a system?

  By heating it up or doing work
• What energy changes occur during a change of state?

  Potential energy changes, kinetic energy remains constant
• What equation determines the energy required to change the temperature of a substance?

  Q = mcΔT
• What do the symbols in the equation Q = mcΔT represent?

  Q - J, m - kg, c - JK^-1, T - K
• What is the equation for the energy required for a change of state?

  Q = ml
• What do the symbols in the equation Q = ml represent?

  Q - J, m - kg, l - Jkg^-1
• What is the Ideal gas equation?

  pV = nRT
• What do the symbols in the Ideal gas equation pV = nRT represent?

  p - Pa, R - 8.31 Jmol^-1K^-1, n - mols, T - K, V - m³
• What is the first law of thermodynamics?

  ΔU = Q - W
• What do Q and W represent in the first law of thermodynamics?

  Q = heat added, W = work done
• What is the specific heat capacity of a substance?

  Energy to raise 1kg by 1K
• What is the specific latent heat of a substance?

  Energy to change state per unit mass