The fluid thermodynamic properties involving partial derivatives are related in some specific correlations with compressibility factor Z

derivative compressibility factors Zp and Zr and specific heat Cp. In order to recommend general formulas and tables for the calculation of ZP and ZT

two general analytical expressions of Zp(O)or(R) and ZT(O)or(R) based on Lee-Kesler equation are developed

and the tables of Zp(O)

Zp(1)

ZT(O)

Zr(1) are provided

over the range Pr=0.1-10

Tr=0.3-4. Using the ZP(O)or(R)

ZT(O)or(R) expressions or tables provided

the thermodynamic properties of non-polar or light polar fluids

such as the exponent of isentropic process

speed of sound

the difference or the ratio of specific heat Cp-Cv

Cp/Cv etc.

can be calculated manually or with a computor. Some calculations of the thermodynamic properties indicated above for CO2

F-22

N2 show that the results are in good agreement with the data published. The error is allowable for engineering applications.