Principle of Corresponding States Experimental observation shows that compressibility factors Z for different fluids exhibit similar behavior when correlated as a function of reduced temperature Tr and reduced pressure Pr.All fluids, when compared at the same reduced temperature and the reduced pressure, have approximately the same compressibility factor (Z)and all deviate from ideal gas behavior to about the same degree.
Internal energy .Internal energy (U) refers to the energy stored in the system by virtue of the configuration and motion of the molecules of the system. *Internal energy is a definite property of the system unlike kinetic energy and potential energy of the system as a whole. *Absolute values of internal energy cannot be measured, only changes from one state to another. *Addition of heat or work to a substance increases the molecular activity, which in turn increases the internal energy. *Specific internal energy represented as internal energy per unit mole or mass is an intensive property. *This form of energy is named internal energy to distinguish it from the kinetic and potential energy of the system resulting from its macroscopic position or motion
ENTROPY 1. The function that is fundamental in the development second law of thermodynamics is entropy 2Entropy is a measure of the disorderness of the system 4A spontaneous process occurring in a closed adiabatic system is accompanied by an increase in entropy. 5For a reversible process occurring in a closed adiabatic system, the entropy change must be zero ,as there is no heat exchange.
compressibility Factor(z) the compressibility factor measure the deviation of a real gas from ideal behavior.it is the ratio of the volume of a real gas at set of specific temperature & pressure to the volume occupied by the gas at the same tem & pressure if it were an ideal gas.
