E-Lecture - Important Points
  • Heat is thermal energy transferred from a hotter system to a cooler system that are in contact.
  • Temperature is a measure of the average kinetic energy of the atoms or molecules in the system.
  • The heat released or absorbed by a body is calculated using the equation: Q = mcΔT
  • Specific heat capacity is the number of joules of heat energy required to raise the temperature of 1 kg of a substance by 1 k

  • The three mechanisms of heat transfer are conduction, convection, and radiation.
  • Conduction occurs within a body or between two bodies in contact.
  • Convection depends on motion of mass from one region of space to another.
  • Radiation is heat transfer by electromagnetic radiation, such as sunshine, with no need for matter to be present in the space between bodies.
  • Heat capacity is the heat required per unit rise in temperature

  • Calorimetry is an experimental method of determining the specific heat capacity of a body by mixing two or more bodies in a calorimeter and apply the law of heat exchange.
  • A phase change occurs when a substance changes state.
  • The critical point is where the liquid and gas phases become indistinguishable.
  • The triple point is where all three states coexist together.
  • Latent heat is energy that is supplied to a substance but does not result in a rise in temperature but does result in a change of phase.
  • Latent heat of fusion

  • Latent heat of vaporization

  • In an internal combustion engine, a mixture of fuel and air is burned in a closed cylinder, inside the engine, contrary to the external combustion engine in which the burning of fuel takes place outside the engine.