Formulas

• Temperature


  A measure of how hot or cold something is
• Thermometer


  Instruments used to measure temperature
• Freezing point of water


  • 0°C, 32°F, 273.15°K
• Boiling point of water


  • 100°C, 212°F, 373.15°K
• Thermal Equilibrium


  When two objects placed in thermal contact will eventually come to the same temperature
• Zeroth Law of Thermodynamics


  If two objects are each in equilibrium with a third object, they are also in equilibrium with each other
• Linear Expansion


  Occurs when an object is heated
• Equation of state


  The relationship between volume, temperature, pressure, and mass of a gas
• Boyle's Law


  The volume of a given amount of gas is inversely proportional to pressure as long as temperature is constant
• Absolute zero temperature (Kelvin scale)


  • The volume becomes zero at -273.15°C
• The triple point


  The only point where all three phases can co-exist in an equilibrium
• Dew point


  The temperature at which the air could be saturated with water
• Humidity is high


  It is hard for any water to evaporate
• Temperature goes below dew point


  Dew, fog or rain may occur
• Diffusion


  Occurs from a region of high concentration towards a region of low concentration / concentration of substances becomes uniform
• Evaporation


  Occurs when the fastest moving molecules escape from the surface of a liquid
• Saturated vapor pressure


  Occurs when two phases are in equilibrium
• Relative humidity


  The ratio of the actual vapor pressure to the saturated vapor pressure
• 1 Cal


  The amount of heat necessary to raise 1g of water by 1 Celsius degree
• Heat


  Energy transferred from one object to another because of the difference in temperature
• Internal energy


  The sum of all the energy of all the molecules in a substance
• Temperature


  Measures molecules' average kinetic energy
• Specific heat


  The amount of heat required to change the temperature of a material is proportional to the mass and to the temperature change
• Closed system


  No mass enters or leaves, but energy may be exchanged
• Open system


  Mass may transfer as well
• Isolated system


  Closed system where no energy in any form is transferred. Heat lost = Heat gained
• Calorimeter


  An instrument that makes quantitative measurement of heat exchange
• Bomb calorimeter


  Measures the thermal energy released when a substance burns
• Heat of fusion


  Heat required to change 1kg of material from solid to liquid
• Heat of vaporization


  Heat required to change 1kg of material from liquid to vapor
• Convection


  Occurs when heat flows by the mass movements of molecules from one place to another
• The sun radiates at a temperature of almost 6000K
• Thermography


  The detailed measurement of radiation from the body
• Heat transfer


  • Conduction
  • Convection
  • Radiation
• Conduction


  Energy is transferred through the collisions of molecules in a substance
• Radiation


  The transfer of energy by electromagnetic waves
• The Law of Conservation of Energy: the change in internal energy of a closed system will be equal to the energy added to the system minus the work done by the system on its surroundings
• Isothermal process


  Temperature does not change
• Adiabatic process


  There is no heat flow into or out of the system
• Isobaric process


  Occurs at constant pressure