ANALYZING OF STUDENTS' MISCONCEPTIONS ON ACID-BASE CHEMISTRY AT SENIOR HIGH SCHOOLS IN MEDAN

Students misconceptions on acid-base chemistry at Senior High Schools in Medan were investigated in this study. The study involved 179 of XI grade students from six different schools in Medan selected based on their accreditation. Students misconceptions on acid base chemistry topic were identified and collected by giving a valid test developed by researcher to the students in form of Acid-Base Chemistry Misconception Test containing 12 open-ended multiple choices. The data collected were processed and categorized based on students achievement and students understanding. It was revealed that students had fifteen misconceptions and eleven sub-misconceptions. From five main concepts investigated in acid-base chemistry, percentage of students responses categorized as specific misconceptions are acid and base concepts (22.07%), pH and pOH concepts (43.58%), ionization degree and equilibrium constant concepts (8.94%), acid-base indicators concept (6.15%), and acid-base titration concept (9.50%). The study also revealed four main students problems in understanding acid-base chemistry namely fragmentation of students understanding, problems with symbols and mathematical formula, difficulties in understanding the context in acid-base chemistry, and problems in generalization.