Acta Didactica Napocensia
Volume 10 Number 4, pages 69-78
Published: 25 December 2017
Problem Solving Instruction for Overcoming Students'
Difficulties in Stoichiometric Problems
Mandina Shadreck, Ochonogor
Chukunoye Enunuwe
Abstract. The study
sought to find out difficulties encountered by high school chemistry students
when solving stoichiometric problems and how these could be overcome by using a
problem-solving approach. The study adopted a quasi-experimental design. 485
participants drawn from 8 highs schools in a local education district in
Zimbabwe participated in the study. A validated stoichiometry achievement test
was used to collect data at pre-test and post-test stages. The researchers also
prepared a difficulty identification index to analyse the difficulties
encountered by students. Quantitative data was analysed using inferential
statistics and ANCOVA. From the findings, the difficulties identified were lack of understanding of the mole concept,
inability to balance chemical equations, use of inconsistent stoichiometric
relationships, identifying the limiting reagent, determination of theoretical
yields and identification of substances in excess. The study also found
that the use of problem-solving instruction as effective in remedying the
identified difficulties in comparison to the conventional lecture method. It
was strongly recommended that chemistry
educators should analyse and understand student difficulties if they are to
assist the learners to become confident and efficient problem solvers.
Furthermore chemistry educators should implement the problem-solving
pedagogical technique as a means of addressing the difficulties students have
in stoichiometry problem-solving.
Key words: stoichiometry; difficulties; problem-solving,
chemistry educators