A four-parameter

Ghoderao-Dalvi-Narayan 2 cubic equation of state (GDN2 CEOS)

is presented which incorporates the following:1. The experimental value of the critical compressibility factor has been used as a fixed input parameter for calculations; 2. All the parameters (

a

b

c

d

) of CEOS are temperature dependent functions in the subcritical region and are temperature independent functions in the supercritical region and; 3. A new α function is introduced with two compound specific parameters which are estimated by matching saturated vapor pressure at two fixed temperature points

T

r

=0.5

0.7. Our formalism enables us to cast three of the four parameters of the CEOS as a function of the remaining parameter. The proposed CEOS is used to predict properties of 334 pure compounds

including saturated vapor pressure and liquid density

compressed liquid density

heat capacities at the constant pressure and volume

enthalpy of vaporization

sound velocity. To calculate thermodynamic properties of a pure compound

the present CEOS require the critical temperature

the critical pressure

the Pitzer's acentric factor

the critical compressibility factor

and two parameters o

f the alpha function. The saturated liquid density predictions for pure fluids are very accurate when compared with GDN1 (Ghoderao-Dalvi-Narayan 1)

MPR (Modified Peng-Robinson)

and PT (Patel-Teja) equations of state. Unlike MPR EOS

the proposed temperature dependent covolume parameter

b

in the present work satisfies all the constraints mentioned in the literature to avoid thermodynamic inconsistencies at the extreme temperature and pressure. Using van der Waals one-fluid mixing rule

the present CEOS is further used to predict bubble pressure and the vapor mole fraction of binary mixtures.