An integral description of chemical reactions taken place under mixing was formulated on the basis of the three-region model pictured in Part I of this study. A mathematically simplified version of the model was developed. It was shown that the converted portion of the material in the dispersion region can be neglected provided that the initial concentration ratio of A and B was less than 0.1, and the effects of micro-and macromixing on the chemical reactions could be represented by two dimensionless number: Da and II. The model was applied to two reacting systems: competitive-consecutive reactions and parallel reactions, Agreement between model prediction and experimental results demonstrated that the present framework, though in simplified form, is capable of describing reactive mixing without loss of any significant features of the process.