In recent years, many countries have adopted a context-based approach for designing science curricula for education at all levels. The aim of this study was to determine the effectiveness of a Context-Based Chemistry Course (CBCC) as compared with traditional/existing instruction, on 11th grade students' learning about chemical equilibrium, "motivation to learn chemistry" and "constructivist learning environment." A mixed-method research design was used. The study group consisted of 104 students in 11th grade at a public high school. "Chemical Equilibrium Achievement Test" (CEAT), "Chemistry Motivation Questionnaire" (CMQ) and "Constructivist Learning Environment Survey" (CLES) were used for quantitative data collection (as pre-test and post-test). Students' opinions about the effects of the CBCC were collected via a questionnaire. Quantitative findings showed that CBCC made a positive impact on students' achievement, motivation to learn chemistry and constructivist learning environment. Students' opinions on the implementation of CBCC showed that CBCC provided authentic applications of chemistry topics, formed relations between chemistry and daily life, concretized chemistry concepts, made concepts highly memorable, and learning more enjoyable in the courses. In summary, results showed that CBCC, compared to traditional/existing instruction, enabled students to learn chemistry concepts more effectively.