ABSTRACT
In the previous chapters, we have dealt with systems consisting essentially of pure substances for which property tables or equations were created. In many practical situations, however, we encounter substances that are not pure or whose composition may change during the process. For example, in the process of making tea we dissolve sugar in hot water, thus changing the concentration of sugar in water. Obviously, the properties of sugared water depend on the sugar content of the solution. It is possible to have an infi nite number of different compositions of the sugar-water mixture. Although the properties of any given composition can be measured and tabulated, it is impractical to do so for all the possible compositions.
