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

Abstract

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.