Critical exponents values for fluids and linear scaled equation of state

Abstract

The behavior of substance in the vicinity of a critical point is the focus of great scienti fic interest. A liquid-liquid phase transition in the supercooled region could influence biochemical or precipitation processes. It is interesting that water in a space is mostly in a supercooled or amorphous ice form. These two forms have similar properties. A parametric linear scaled equation of state is used to describe thermophysical properties in the critical point vicinity. A values correction of critical exponents that were calculated from Ising model or were experimentally found, influences values of the scaled equation constants. Paper deals with a dependence of these scaled equation linearity on critical exponents. Several critical exponents sets gained either using theoretical calculations from Ising model or experimentaly, were analyzed. A requirement on an accurate choice of critical exponents or a need to recalculate the parametric model coefficients is emphasized in the paper.

Keywords

• critical point
• equation of state
• critical exponents
• scaled equation