Thermodynamics :  Temperature, Heat, and Work
Thermodynamics - The study of the relationship between heat, work, and other forms of energy.

Thermochemistry - A branch of thermodynamics which focuses on the study of heat given off or absorbed in a chemical reaction.

Temperature - An intensive property of matter; a quantitative measurement of the degree to which an object is either "hot" or "cold".

  1. There are 3 scales for measuring temperature
Conversion Factors for Temperature

Heat (q)

Caloric Theory of Heat
  • Canon-boring experiment showed that friction was an inexhaustible source of heat.  He concluded that heat, therefore, was not conserved. 
  • This experiment served as a starting point for the development of a new theory, the kinetic theory of heat. 
Kinetic Theory of Heat
where R is the ideal gas constant (0.0821 L-atm/mol-K) and T is temperature (Kelvin)
When heat enters a system, it causes an increase in the speed
at which the particles in the system move.

Work (w)
Heat and Work
  • Did several experiments measuring how much heat could be produced from a given amount of heat. 
  • In his most well-known experiment, Joule used falling weights connected to a rope wrapped around rotating paddles.  The paddles were placed in either water, mercury, or oil and he measured the change in temperature of these liquids when the weights were dropped. 
  • One joule is by definition the work done when a force of one newton (N) is used to move an object one meter (m): 
Next:  "First Law of Thermodynamics"