Investigating High School Students’ Understanding of Chemical Equilibrium Concepts

This study investigated the year 12 students’ (N = 56) understanding of chemical
equilibrium concepts after instruction using two conceptual tests, the Chemical
Equilibrium Conceptual Test 1(CECT-1) consisting of nine two-tier multiple-choice items
and the Chemical Equilibrium Conceptual Test 2(CECT-2) consisting of four structured
questions. Both these tests were administered before and after the intervention.
Students’ responses to the items in both the instruments indicated limited
understanding of the various concepts related to chemical equilibrium. Less than 50% of
the students provided correct responses to four of the nine items in the CECT-1. The
total scores in the CECT-1 ranged from 0 to 8 with a mean score of 4.14 (out of a
maximum of 9). In the CECT-2 the total scores ranged from 7 to 17 with a mean score of
11.0 out of a maximum score of 22. Almost half the number of students (44.6%) scored
less than 50% of the total marks in the CECT-2; only 0% to 42.9% of students scored the
maximum possible marks for each of the four items while achievement in all four items
of the CECT-2 was below 50%. The findings will be valuable and assist teachers in
planning their instruction on chemical equilibrium by taking into consideration
students’ preconceptions about the topic.