thermodynamics

Thermodynamic Systems and Processes Summary• A thermodynamic system is a collection of matter and space with its boundariesdefined in such a way that the energy transfer across the boundaries can be bestunderstood.• Surroundings are everything not in the system being studied.• Systems are classified into one of three groups:Isolated system - neither mass nor energy can cross theboundariesClosed system - only energy can cross the boundariesOpen system - both mass and energy can cross theboundaries• A control volume is a fixed region of space that is studied as a thermodynamicsystem.• Steady state refers to a condition where the properties at any given point within thesystem are constant over time. Neither mass nor energy are accumulating within thesystem.• A thermodynamic process is the succession of states that a system passes through.Processes can be described by any of the following terms:Cyclic process - a series of processes that results in the systemreturning to its original stateReversible process - a process that can be reversed resulting in no changein the system or surroundingsIrreversible process - a process that, if reversed, would result in a change tothe system or surroundingsAdiabatic process - a process in which there is no heat transfer across thesystem boundariesIsentropic process - a process in which the entropy of the system remainsunchangedPolytropic process - the plot of Log P vs. Log V is a straight line, PVn =constantThrottling process - a process in which enthalpy is constant h1 = h2, work= 0, and which is adiabatic, Q=0.