 1st Law of Thermodynamics – conservation of energy
 ?U = W + Q
 W =  (area bounded by the PV graph and the xaxis)
 Expansion of a gas is negative work done since the internal energy of the gas is reduced unless heat is added
 Compression of the gas by an external agent is positive work
 Four gas processes – isothermal, adiabatic, isobaric, and isovolumetric LAB – PV measurements of a confined gas
 1st Law “zero” conditions for isothermal, adiabatic, and isovolumetric
 PV diagrams
 State variables: P, V, U, T, and S (moving from an initial position’s values to a final position’s values)
 Understand when heat will be added or removed during compressions/expansions of each type
 Closed cycles VIDEO DISCUSSION – Discovery of Energy/Heat
 Clockwise cycles define net Work as negative
 VIDEO DISCUSSION – James Watt and the Steam Engine
 U equals zero
 Qnet = Wnet
 Efficiency formulas eff = W/Qin = 1 – (Qout/Qin)
 Qin = Qout + W
 Carnot Cycle and ideal efficiency
 2nd Law of Thermodynamics
 If an isolated system undergoes spontaneous change there is an increase in the disorder of the system
 S = Q/T S = k ln(O) Suniverse = 0
 Entropy is a statistical, macro measurement of a system’s disorder – not reversible without doing work on the system
 3rd Law of Thermodynamics
 Absolute Zero cannot be reached in a finite number of steps (it is a mathematical limit, not an attainable temperature)
