The Laws for Open Reacting Systems

In this section we extend the development in 7.4 to reactions taking place in open systems. First we develop the open-system material-balance equations for reactions ( 7.5.1) and then we develop the combined laws ( 7.5.2). 

1 Stuff Equation for Material in a Single Open Phase 

Open-system chemical reactions cause changes in many important situations, such as meteorological and biological systems [1]. Early studies of such systems raised questions about the generality of the laws of thermodynamics because workers failed to distinguish open systems from those that are closed. This confusion was largely resolved by Prigogine, whose work on these problems contributed to his Nobel Prize. 

Consider an open system having any number of inlets a and any number of outlets p. For such a system, the general stuff equation (1.4.1) can be written in terms of the number of moles of species i, 

Flere the superscript gen refers to generation of species i, con refers to consumption, and acc refers to accumulation of i in the system. When chemical reactions are occur-ring, the difference between the generation and consumption terms reflects the net effect of reactions (rxn). Moreover, we already have an expression (7.4.15) for the change in species mole numbers due to reactions here we write (7.4.15) in the form 

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