Abstract In order to solve some puzzles in the teaching of titration of mixture of acids (bases) and polyacid (base), some ideas are put forward. (1) On the basis of understanding the titration reaction, we should make full use of the titration curve as a powerful tool to solve all kinds of problems. (2) In the process of teaching, we should follow the principle from the easier to the more advanced. On the basis of fully teaching the titration of single monoacid, the teaching contents can be arranged in the following order: titration of mixed monoacids with alkali, titration of polyacid with alkali, and titration of complex mixture of acids with alkali. Because the rules are similar, only a brief introduction of titration of base with strong acid is needed after the students have finished learning titration of acid with alkali. In addition, a new method for the obtaining titration curve of complex acids (bases) system by splicing single monoacid (base) titration curves without complex calculation is proposed. Although the obtained curve is not very accurate, it is sufficient to provide strong support for the possibility judgment of titration analysis and the selection of indicators.
CHEN Dong-Nian. Teaching Reflection on Titration of Mixed Acids and Titration of Polyacid[J]. Chinese Journal of Chemical Education, 2022, 43(2): 125-129.
