Basic Calculations of Physical Properties

In the absence of a single accurate theory representing the physical reality of liquids and gases and, consequently, all their physical properties, a property can be calculated in various ways. 

A panoply of methods whose results can be widely scattered are available to the process engineer not knowing the pitfalls attached to this activity, he would like to have a unique method or an exact guideline for applying these methods. 

Using computer programs compiicates the problem because the calculation accuracy is never given for commercial reasons. Furthermore, the ways in which the methods are executed are not explicit and the data banks are often considered secret and inaccessible. 

The nature of the calculational bases, that is, the components and conditions of temperature and pressure, are too varied for it to be possible to make absolute recommendations as to the choice of methods. 

Chapter 4. METHODS FOR THE CaLCULATDN OF HYDRQCmON PhYS AL PROPERTIES 107 

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