The Future of Education

An inquiry-based laboratory activity was designed to promote high school students’ conceptual understanding of stoichiometry. There were three developed lesson plans of the inquiry-based laboratory activity that covered four topics of stoichiometry: a) the relationship between mole ratio and coefficient in a chemical equation, b) limiting reagents, c) calculation in a chemical equation, and d) percent yield. The lesson plans were implemented to 23 Thai high school students in science and mathematics program who enrolled in chemistry course and collected data using one group pretest-posttest design. Data collecting tools consisted of two-tier diagnostic tests and semi-structured interview questions. The results from the two-tier diagnostic tests using a dependent sample t-test analysis indicate that the average posttest score (41.78 ± 10.07) was significantly higher than the average pretest score (5.74 ± 4.84). Then, students’ responses to each two-tier question were analyzed to find a degree of students’ understanding related to each topic. Overall, students that hold sound understanding (SU) and partial understanding (PU) were increased by 66.48 %, especially in the calculation in a chemical equation topic. While students who hold specific misconception (SM) and no understanding (NU) were decreased by 75.08 %, especially in the percent yield topic. The findings were supported by the interview results, in which students can perceive the laboratory activity visualized how the content knowledge of stoichiometry is related to the experiments, and provided them to gain in-depth understandings of the topics.

Keywords: High school Chemistry, Inquiry-Based Laboratory, Conceptual Understanding.