THERMODYNAMICS

• Thermodynamics

  1st Law (Conservation of Energy)

  • energy can neither be created nor destroyed
  • it can only change forms

  2nd Law

  • entropy of an isolated system always increases
  • entropy or S, is the degree of disorder

  3rd Law

  • entropy at -273.15K (absolute zero temperature is zero
  • there can be no temperature lower than absolute zero
• Hess' law

  • enthalpy is the heat transferred between systems and surroundings at constant pressure
• Specific Heat

  • specific heat is the amount of energy needed to raise the temperature of the substance by one degree
  • J/kg-C; decreases as mass and temperature to be attained increases
  • temperature - hotness or coldness
  • heat - total kinetic energy of molecules
  • Equation: Q = mcΔT
• Boiling Point

  • the temperature where liquids turns into gas
  • also requires the addition of heat
  • boiling point of water: 100 °C
• Melting Point

  • the temperature where solid becomes liquid
  • this change from solid to liquid requires heat
  • melting point of water: 0°C