Perfect-gas and Residual Properties

For generality, we consider again a mixture of v eomponents eharaeterised by amounts of substance i, tij, (denoted by the veetor ), temperature T, 

The usual choice is to adopt T,p, ) as the independent variables and thus follow eq 3.12. Nevertheless, equations of state are usually formulated with T, V, nf as the independent variables, in which case one must first evaluate (T, V, ) and then apply eq 3.14 to obtain the desired residual properties at the specified temperature, pressure and composition. A necessary step in this procedure is evaluation, from the chosen equation of state, of the volume corresponding to the specified (T, p, / ). 

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