Response reactions: definition, derivation and classification based on thecomposition of the participating species

An interpretive concept has recently been published to rationalize the chan ges generated by the change of control parameters (pressure, temperature, c omposition) in complex equilibrium systems. It was proven that all of the s ensitivity coefficients (and many other thermodynamically important quantit ies) may be split into terms which are uniquely assigned to the so-called r esponse reactions (RERs). RERs were defined by the missing species and thei r derivation was based on the stoichiometrically independent reactions (SIR s). In this paper we redefine RERs with the help of the participating speci es and derive them from the composition of the participating species. This new way of definition and derivation leads to the classification of RERs, w hich was not possible before and helps to understand the underlying chemist ry of governing and regulating the equilibrium systems. The formulae are pr esented in general form, but some examples are also given to rationalize th eir meaning.