ABSTRACT

This chapter contains the basic concepts needed for the mathematical formulation of chemical reactions and calculation of species concentrations. Although they are recently included in some geochemical codes (Parkhurst and Appelo, 1999), isotope reactions and distributions are outside the scope of this chapter. While this is not strictly necessary, a vector and matrix notation is adopted here because it facilitates concise writing, which will be critical in subsequent chapters. Matrix notation also facilitates the use of linear algebra techniques, such as multiplication of matrices and the inverse, rank and kernel of a matrix. We hope that the chapter can be read without being familiar with these techniques. Still, algorithmically oriented readers may consult any of the various textbooks on this field (e.g., Meyer, 2000).