Uneven Mastery across Chemistry Competencies: Evidence from Grade 11 Stem Students in General Chemistry 2

This study investigated the mastery levels of Grade 11 STEM learners across the Third- Quarter competencies of General Chemistry 2 to identify areas requiring targeted instructional support. Using a descriptive quantitative research design, data were collected from fifty (50) Grade 11 STEM students enrolled in General Chemistry 2 at a private secondary school in the Philippines. A researcher- developed, MELC-aligned achievement test consisting of fifty multiple-choice items was employed to assess learners’ conceptual and procedural understanding. The instrument underwent expert validation, pilot testing, and reliability analysis, yielding a Kuder–Richardson Formula 20 (KR-20) coefficient of 0.844. The results revealed varying levels of mastery across the fifteen assessed competencies. Most competencies were classified as Mastered or Nearly Mastered, particularly those related to phase changes, solution chemistry, thermochemistry, and chemical kinetics, indicating stronger performance in conceptually oriented and qualitative topics. In contrast, the lowest mastery levels were observed in competencies requiring the integration of conceptual understanding and mathematical application, notably the quantitative treatment of colligative properties and the application of Hess’s Law in determining heat changes. These competencies posed challenges due to their reliance on multi-step problem solving, numerical computation, and abstract reasoning. The findings underscore the uneven nature of chemistry mastery across competencies and highlight the need for strand-responsive instructional strategies that emphasize guided problem-solving, visual representations, and contextualized learning experiences. The study provides empirical baseline data that can inform the development of targeted instructional interventions, such as Strategic Intervention Materials, to enhance learners’ mastery of quantitatively demanding chemistry concepts and improve overall achievement in General Chemistry 2.

Least Mastered Competency, Mastery Level, MELCs

1. Abao, T. G., Pañares, J. D., & Gonzales, R. (2023). Effects of virtual laboratory instruction on students’ chemistry performance. International Journal of Science and Management Studies, 6(6), 14–20. [Google Scholar] [Crossref]

2. Almahdawi, M. (2025). Factors influencing high school students’ understanding of organic qualitative analysis. Eurasia Journal of Mathematics, Science and Technology Education. [Google Scholar] [Crossref]

3. Andres, R. M., & Gonzales, A. L. (2022). Identifying least mastered competencies as basis for instructional intervention in science. Science Education International, 33(2), 159–168. https://doi.org/10.33828/sei.v33.i2.7 [Google Scholar] [Crossref]

4. Ausubel, D. P. (1968). Educational psychology: A cognitive view. Holt, Rinehart & Winston. [Google Scholar] [Crossref]

5. Benedicto, S. (2024). Addressing least mastered competencies in Earth and Life Science through problem- based laboratory activities. Journal of Innovation in Psychology, Education and Didactics, 28(2), 75–88. [Google Scholar] [Crossref]

6. Beruin, L. C. (2022). STEM students’ conceptions and experiences of online learning during the COVID-19 pandemic. Journal of Pedagogical Research, 6(4), 143–167. https://doi.org/10.33902/JPR.202217716 [Google Scholar] [Crossref]

7. Biggs, J., & Tang, C. (2011). Teaching for quality learning at university (4th ed.). Open University Press. [Google Scholar] [Crossref]

8. Broad, H., McGrath, C., & Thomson, A. (2023). Impact of blended learning on chemistry students’ conceptual understanding during the pandemic. Journal of Chemical Education, 100(3), 1123–1134. [Google Scholar] [Crossref]

9. Dela Cruz, J. P. (2020). Mastery level of STEM-related competencies among Grade 11 learners. Asia Pacific Journal of Multidisciplinary Research, 8(3), 45–52. [Google Scholar] [Crossref]

10. Gilbert, J. K., & Treagust, D. F. (2009). Multiple representations in chemical education. Springer. https://doi.org/10.1007/978-1-4020-8872-8 [Google Scholar] [Crossref]

11. Johnstone, A. H. (1991). Why is science difficult to learn? Things are seldom what they seem. Journal of Computer Assisted Learning, 7(2), 75–83. https://doi.org/10.1111/j.1365-2729.1991.tb00230.x [Google Scholar] [Crossref]

12. Jusniar. (2020). Students’ misconceptions about rates of reaction and equilibrium relationships. European Journal of Educational Research, 9(1), 371–383. [Google Scholar] [Crossref]

13. Kumar, S. (2025). Assessing secondary students’ misconceptions in acid–base chemistry: A diagnostic approach. International Journal of Scientific Research in Education, 2(2), 137–150. [Google Scholar] [Crossref]

14. Llego, M. A. (2022). Most Essential Learning Competencies (MELCs) for School Year 2022–2023. TeacherPH. https://www.teacherph.com/melcs/ [Google Scholar] [Crossref]

15. Lopez, E. C. R., Ramirez, C. A., & Flores, A. M. (2025). Predictors of academic performance in chemical engineering courses. International Journal of Engineering Education. [Google Scholar] [Crossref]

16. Lucena Rodríguez, C., Mula-Falcón, J., Domingo Segovia, J., & Cruz-González, C. (2021). The effects of COVID-19 on science education: A thematic review of international research. Journal of Turkish Science Education, 18(Special Issue), 26–45. https://doi.org/10.36681/tused.2021.70 [Google Scholar] [Crossref]

17. Mai, Y., Qian, Y., Lan, H., & Li, L. (2021). Upper-secondary students’ concept organization related to chemical equilibrium. Journal of Baltic Science Education, 20(3), 443–455. https://doi.org/10.33225/jbse/21.20.443 [Google Scholar] [Crossref]

18. Mamintal, A. (2024). Development and validation of a chemistry-based e-module using least mastered competencies. American Journal of Multidisciplinary Research and Innovation, 3(6), 49–61. [Google Scholar] [Crossref]

19. Melitante, K. J. A., Nabua, E. B., Salic-Hairulla, M., Fernandez, M. J., & Rosales, V. (2025). Profiling least mastered competencies among Grade 11 non-STEM learners: Basis for targeted instructional intervention. International Journal of Research and Innovation in Social Science, 9(4), 6541–6549. [Google Scholar] [Crossref]

20. Munawwarah, M. (2025). Unveiling misconceptions in core chemistry topics: A systematic study. Journal of Science and Geoscience Pedagogy, 4(1), 1–15. [Google Scholar] [Crossref]

21. Murni, A. T., Syaful, H., & Pratiwi, R. (2022). The impact of inquiry-based modules on students’ understanding of reaction rates. International Journal of Instruction, 15(4), 245–260. [Google Scholar] [Crossref]

22. Navalta, E. R., Nabua, E. B., Micutuan, R. P. G., Abdurahman, M. M., & Poblete, T. C. (2025). Learning competencies of Grade 11 STEM learners in organic chemistry. International Journal of Research and Innovation in Social Science, 9(1), 3363–3373. [Google Scholar] [Crossref]

23. Nguyen, T. L., Johar, N. A., & Ismail, R. (2021). Enhancing chemistry education through contextual learning: A review of recent studies. Journal of Chemical Education Research, 5(1), 12–22. [Google Scholar] [Crossref]

24. Nurwidodo, N., Susanti, R., & Widodo, W. (2023). Science learning in the COVID-19 era: A systematic literature review. Eurasia Journal of Mathematics, Science and Technology Education, 19(4), 1–12. [Google Scholar] [Crossref]

25. Ocanay, L. C., Santos, M., & Villar, E. (2022). Performance trends of senior high school learners in General Chemistry 2. Philippine Journal of Science Education, 11(1), 55–67. [Google Scholar] [Crossref]

26. Oladejo, A. I., Ademola, I. A., Ayanwale, M. A., & Tobih, D. (2023). Concept difficulty in secondary school chemistry: Influence of gender and school characteristics. Journal of Technology and Science Education, 13(1), 255–275. [Google Scholar] [Crossref]

27. Organisation for Economic Co-operation and Development. (2019). OECD learning compass 2030: A series of concept notes. OECD Publishing. [Google Scholar] [Crossref]

28. Ortiz, F. J. A., Dalayap, J. M. R., & Vergara, D. A. (2025). Chemistry learning challenges and coping strategies among STEM and non-STEM pre-service teachers. ASEAN Journal for Science Education, 4(2), 109–120. [Google Scholar] [Crossref]

29. Paraguas, S. W. (2025). Self-efficacy and general chemistry problem-solving proficiency among first-year college students. Canadian Journal of Educational and Social Studies, 5(2), 44–60. [Google Scholar] [Crossref]

30. Poblete, T. C., Nabua, E. B., Abdurahman, M. M., Navalta, E. R., Jr., & Micutuan, R. P. G. (2025). Grade 11 STEM learners’ learning competencies and motivation in General Chemistry. International Journal of Research and Innovation in Social Science, 9(1), 3763–3774. [Google Scholar] [Crossref]

31. Pratomo, H., Fitriyana, N., & Wiyarsi, A. (2025). Mapping chemistry learning difficulties across grade levels: A cross-sectional study. Journal of Education and Learning, 19(2), 909–920. [Google Scholar] [Crossref]

32. Rahayu, I., Fitria, N., & Rahman, A. (2024). Analysis of misconceptions in factors affecting reaction rate among high school students. KnE Social Sciences, 9(1), 276–287. [Google Scholar] [Crossref]

33. Rahmawati, Y., Fitria, R., & Utami, S. (2022). Enhancing conceptual understanding of chemical equilibrium using PhET simulations. Journal of Technology and Science Education, 12(2), 334–347. [Google Scholar] [Crossref]

34. Ramirez, H. J., & Paderna, E. E. (2024). Students’ perceived mastery and relevance of chemistry competencies toward sustainable development. Chemistry Teacher International, 6(2). [Google Scholar] [Crossref]

35. Redhana, I. W. (2021). Green chemistry laboratory activities and their effects on students’ understanding of equilibrium. Journal of Turkish Science Education, 18(3), 395–410. [Google Scholar] [Crossref]

36. Santos, J. T. D., Lim, R. R., & Rogayan, D. V., Jr. (2021). Least mastered competencies in biology: Basis for instructional planning. Jurnal Pendidikan Biologi Indonesia, 7(3), 283–298. [Google Scholar] [Crossref]

37. Sayre, E. D., Nabua, E. B., Salic-Hairulla, M., Alcopra, A., & Fernandez, M. J. (2025). Assessing General Chemistry learning gaps: A needs assessment of competency mastery among Grade 11 learners. International Journal of Research and Innovation in Social Science. [Google Scholar] [Crossref]

38. Sibomana, A., Karegeya, C., & Sentongo, J. (2021). Factors affecting secondary school students’ academic achievements in chemistry. International Journal of Learning, Teaching and Educational Research, 20(12), 114–126. https://doi.org/10.26803/ijlter.20.12.7 [Google Scholar] [Crossref]

39. Solas, E. P. C. (2025). Factors affecting university students’ performance in first-year physical chemistry. Caribbean Educational and Social Studies Review. [Google Scholar] [Crossref]

40. Suparman, A. R., Rohaeti, E., & Wening, S. (2024). Student misconception in chemistry: A systematic literature review. Pegem Journal of Education and Instruction, 14(2), 238–252. https://doi.org/10.47750/pegegog.14.02.28 [Google Scholar] [Crossref]

41. Taber, K. S. (2002). Chemical misconceptions: Prevention, diagnosis and cure (Vol. 1). Royal Society of Chemistry. [Google Scholar] [Crossref]

42. Taglorin, H. L. L., Nabua, E. B., Latonio, B. C., & Bolocon, A., Jr. (2025). Least mastered competencies in Grade 10 chemistry and associated motivation levels. International Journal of Research and Innovation in Social Science, 9(2), 1008–1021. [Google Scholar] [Crossref]

43. Talanquer, V. (2011). Macro, submicro, and symbolic: The many faces of the chemistry “triplet.” International Journal of Science Education, 33(2), 179–195. https://doi.org/10.1080/09500690903386435 [Google Scholar] [Crossref]

44. Walag, A. M. P., Nabua, E. B., Micutuan, R. P. G., & Abdurahman, M. M. (2025). Learning competencies of Grade 11 STEM learners in organic chemistry: Basis for strategic intervention. International Journal of Research and Innovation in Social Science, 9(1), 3363–3373. [Google Scholar] [Crossref]

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