Titrimetric analysis involved in polybasic acid-base and asymmetric oxidation-reduction pair

In order to understand titrimetric analysis involved in polybasic acid-base and asymmetric oxidationreduction pair regularly,based on Henderson-Hasselbalch equation and Nernst equation,and investigated into the most general circumstance,their titration equation and end point error were explored and expressed as more systematic and perfecter mathematical form when matter conservation,proton conservation and electron conservation were used as basic principle.The results have certain reference value,titration index f is the function of pH of system for acid-base titration or equilibrium potential E of system for oxidation-reduction titration;end point error E_t is related to not only the difference of pH of system for acid-base titration or equilibrium potential E of system for oxidation-reduction titration between the end point and the stoichiometric point but also the ratio of distribution indexδbetween dominant types of substance to be examined at the stoichiometric point.