Thermodynamics Thermal Processes The 2 nd Law of Thermodynamics Entropy

Isovolumetric Processes No change in volume so no ____ done on system Change in system energy equals _____ transfer

Isothermal Process ___________ of system remains constant Internal energy of system remains _________ Integrating P  V gives the work done on the environment

Heat Engines Working substance goes through ______ process 1.Energy transferred by heat from ____ reservoir 2.Work done by ________ 3.Energy expelled by heat to _____ reservoir  U = 0 so Fig. 12.9, p

Heat Engine Efficiency If working substance is a gas, work done in one cycle is ____ _______ in PV diagram Thermal __________ is work done divided by energy absorbed Fig , p. 399

Refrigerators and Heat Pumps Heat engine operating in ________ Can be used to cool the ____ reservoir or warm the ____ reservoir Fig , p. 403

2 nd Law of Thermodynamics No heat engine operating in a cycle can absorb energy from a reservoir and use it _______ for the performance of an _____ amount of work. The efficiency of heat engines is always _____ than one. If two systems are in thermal contact, net thermal energy transfers spontaneously by ______ from the hotter system to the colder system.

Reversible vs. Irreverisble Reversible Process: every state along the path is an ____________ state. System can revert to initial state by reversing path. Real processes are always ____________ (although some are almost reversible).

Carnot Cycle Fig , p. 406Fig , p. 407

Entropy A ______ variable related to the 2 nd Law of Thermodynamics Energy absorbed/expelled during a ________, isothermal process between 2 equilibrium states defines _______ in entropy The entropy of the universe increases in all natural processes

Entropy and Disorder Disorderly arrangement is more _________ Isolated systems tend toward greater _______ Entropy is a ________ of disorder W is the ____________ that a system has a particular configuration