Glossary of Thermodynamic Terms

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van der Waal's EOS The original cubic EOS, the van der Waals EOS is not empirical in nature, but has a theoretical basis.  The derivation of the van der Waals EOS yields two parameters that are functions of the critical temperature and pressure.  One of the parameters accounts for the attractive forces between the molecules and the other parameter represents the volume that the molecules themselves occupy. 2F1 , 4 , 5 , 6
vapor A species that is in the gas phase but is below its critical temperature.  In practical terms, this means that if we could raise the pressure high enough, the vapor would condense.  A vapor is said to be "condensable". 2B2
vapor saturated 2B2 , 4 , 5 , 6 , 8
vapor superheated 2B2 , 4
vapor compression refrigeration cycle ideal 10B2 , 3
vapor compression refrigeration cycle non-ideal 10B4
vapor pressure The pressure that a pure liquid COULD overcome in order to boil.  Vapor pressure depends on temperature only.  If we keep the temperature constant and begin reducing the pressure starting from a very high pressure, then the vapor pressure at our fixed temperature is the pressure at which the liquid begins to boil (first bubble of vapor forms).  [atm, Pa, bar,...] 2B2 , 6, 2C2, 2D2 , 6 , 8 , 9
vapor-compression refrigeration cascade 10C2 - 4
vapor-compression refrigeration cascade, COP of 10C4
vapor-compression refrigeration multistage 10C5 , 6
vaporization Vaporization is a general term that includes both boiling and evaporation.  Vaporization is a process in which a molecule makes the transition from a liquid phase into the gas phase either by boiling or evaporation. 2B7, 2D5, 
vaporization latent heat of 3E2 - 13
vaporize 2D1
vapor-liquid equilibrium 2B2, 2D1, 
vapor-liquid equilibrium curve 2B8
velocity 5A4
velocity profile 5A4
velocity profile average 5A5
velocity profile parabolic 5A4
velocity profile uniform 5A4
vibrational energy The energy associated with the atoms of a polyatomic molecule vibrating about their common center of mass.  This refers to the stretching, flexing and deformation the molecule and its bonds. 2A4
Virial coefficient first 2F2 , 3
Virial coefficient second 2F2 , 3
Virial EOS The Virial EOS is a power series expansion in terms of the inverse of the molar volume.  The parameters of the Virial EOS can be interpreted in terms of statistical mechanics.  The 2nd Virial Coefficient, B, is widely tabulated and its value for a pure compound at a given temperature can be estimated using the critical temperature and pressure and the Pitzer Accentric Factor. 2F1 - 3
volume [m^3] 1D1
volume Ideal Critical Molar The molar volume at of a pure substance predicted by the Ideal Gas EOS at the critical temperature and pressure of that substance.  [ L/mol ] 2E7
volume Ideal Reduced Molar The ratio of the molar volume of a substance to the ideal critical molar volume of the same substance. 2E8
volume Critical Molar The molar volume at of a pure substance when it exists at the critical temperature and pressure of that substance.  [ L/mol ] 2E7
volume molar The total volume of a system divided by the number of moles in the system.  [ L/mole , ft^3/lbmole ] 1D1, 2B1, 2E1
volume specific The total volume of a system divided by the total mass in the system.  [ m^3/kg , ft^3/lbm ] 1D1, 2B1, 2C2
volumetric flow rate 5A5, 5B8,