          # Reduced properties

• in thermodynamics, the reduced properties of a fluid are a set of state variables scaled by the fluid's state properties at its critical point. these dimensionless thermodynamic coordinates, taken together with a substance's compressibility factor, provide the basis for the simplest form of the theorem of corresponding states.

reduced properties are also used to define the peng–robinson equation of state, a model designed to provide reasonable accuracy near the critical point. they are also used to critical exponents, which describe the behaviour of physical quantities near continuous phase transitions.

• reduced pressure
• reduced temperature
• reduced specific volume
## Thermodynamics The classical Carnot heat engine Branches Classical Statistical Chemical Quantum thermodynamics Equilibrium / Non-equilibrium Laws Zeroth First Second Third Systems State Equation of state Ideal gas Real gas State of matter Equilibrium Control volume Instruments Processes Isobaric Isochoric Isothermal Adiabatic Isentropic Isenthalpic Quasistatic Polytropic Free expansion Reversibility Irreversibility Endoreversibility Cycles Heat engines Heat pumps Thermal efficiency System propertiesNote: Conjugate variables in italics Property diagrams Intensive and extensive properties Process functions Work Heat Functions of state Temperature / Entropy (introduction) Pressure / Volume Chemical potential / Particle number Vapor quality Reduced properties Material properties Property databases Specific heat capacity  $c=$ $T$ $\partial S$ $N$ $\partial T$ Compressibility  $\beta =-$ $1$ $\partial V$ $V$ $\partial p$ Thermal expansion  $\alpha =$ $1$ $\partial V$ $V$ $\partial T$ Equations Carnot's theorem Clausius theorem Fundamental relation Ideal gas law Maxwell relations Onsager reciprocal relations Bridgman's equations Table of thermodynamic equations Potentials Free energy Free entropy Internal energy$U(S,V)$ Enthalpy$H(S,p)=U+pV$ Helmholtz free energy$A(T,V)=U-TS$ Gibbs free energy$G(T,p)=H-TS$ HistoryCulture History General Entropy Gas laws "Perpetual motion" machines Philosophy Entropy and time Entropy and life Brownian ratchet Maxwell's demon Heat death paradox Loschmidt's paradox Synergetics Theories Caloric theory Theory of heat ("living force") Mechanical equivalent of heat Motive power Key publications "An Experimental EnquiryConcerning ... Heat" "On the Equilibrium ofHeterogeneous Substances" "Reflections on theMotive Power of Fire" Timelines Thermodynamics Heat engines ArtEducation Maxwell's thermodynamic surface Entropy as energy dispersal Scientists Bernoulli Boltzmann Carnot Clapeyron Clausius Carathéodory Duhem Gibbs von Helmholtz Joule Maxwell von Mayer Onsager Rankine Smeaton Stahl Thompson Thomson van der Waals Waterston Book Categoryvt In thermodynamics, the reduced properties of a fluid are a set of state variables scaled by the fluid's state properties at its critical point. These dimensionless thermodynamic coordinates, taken together with a substance's compressibility factor, provide the basis for the simplest form of the theorem of corresponding states. Reduced properties are also used to define the Peng–Robinson equation of state, a model designed to provide reasonable accuracy near the critical point. They are also used to critical exponents, which describe the behaviour of physical quantities near continuous phase transitions. Contents 1 Reduced pressure 2 Reduced temperature 3 Reduced specific volume 4 See also 5 References  