Thermodynamics System Surroundings - + Thermo = dynamics = heat or energy movement

System Surroundings - + Open systems mass and energy Closed systems energy Isolated systems no exchange

1st Law of Thermodynamics  E universe = = 0  E system = Energy is exchanged as : heat work  E = q + w Energy can not be created or destroyed  E universe = 0  E system +  E surroundings -  E surroundings = q = w E = internal energy =  K.E. + P.E.

heat If T 1 > T 2 System at T 1 Surroundings at T 2 flow of energy along a T gradient q system 0 Exothermic reaction a) > b) < c) = > 0 q surroundings

heat If T 1 < T 2 System at T 1 Surroundings at T 2 flow of energy along a T gradient q system Endothermic reaction > 0 q surroundings < 0

work Electrical work Mechanical work =force x distance force =P x m 2 distance =m work == P x V W system = - VVVV pressure x area = Px m 2 x m P ext

State Functions Property that depends only on the initial and final states Temperature, T : raise T from 298  300 K  T = T final - T initial = : raise T 298  500 K  T = T final - T initial = = 2 K path 1 path 2 lower T from 500  300 K = 2 K P, V, Tstate fixed by 2 of theseindependent

Extensive v.s. Intensive Extensive: Proportional to the mass of the system Intensive: Independent of the mass of the system Temperature: Intensive or Extensive Volume : Pressure: Internal Energy: Intensive or Extensive