Abstract:

Due to the facts that textbook-obedience and termwise experimenting dominate in the general chemistry laboratory classrooms, we have designed and carried out the problem-oriented teaching in order to improve the motivation of learning among the students, where the student-centered exploratory studying and practicing mode is highly desired. Problem-oriented teaching does not lead to exclusive resolutions to specific problems or experiments. Instead, it is supposed to induce multiple choices among student groups to complete experiments or resolve problems, where in-group/between-group discussions and practices would greatly activate the experimenting processes. Therefore, the sense of personal acquisition and self-progression during learning in laboratory classrooms can be easily achieved, while the good laboratory teaching will be realized as well. In this paper, we set up a problem-oriented teaching in optimizing the titration condition during measuring the copper content of K₂[Cu(C₂O₄)₂] using PAN (1-(2-pyridylazo)-2-naphthol) as the indicator. Grouping practices and experiments finally produced complementary results, as well as the satisfactory teaching and learning impacts.

Key words: Laboratory teaching, Problem-oriented teaching, Measurement of copper content, PAN indicator