Mastery Gaps in Acid-Base: A Need Assessment of Grade 12 Senior High School Students

Abstract

Acid–base chemistry is a foundational topic in senior high school curricula, underpinning advanced concepts in chemical reactions, equilibria, and analytical applications. Despite its importance, learners frequently exhibit difficulties in understanding and applying acid–base principles, particularly in computational and conceptual contexts. This study aimed to assess the level of mastery of Grade 12 students in acids and bases and to identify the least mastered competencies through a comprehensive needs assessment. Data were collected from fifty (50) purposively selected students at Kapatagan National High School using a 30-item validated multiple-choice diagnostic test aligned with the Department of Education’s Most Essential Learning Competencies (MELCs). Descriptive quantitative analyses, including mean scores, standard deviations, and mastery level interpretations, were employed to evaluate performance. Results indicated that the overall performance of learners was low, with 92% failing to meet expectations and only 8% achieving a fairly satisfactory level. Learners demonstrated Low Mastery in fundamental definitions of Arrhenius, Brønsted–Lowry, and Lewis acids and bases (MPS = 77.5), while application- and computation-based competencies, including buffer systems, Henderson–Hasselbalch calculations, and salt hydrolysis, were identified as least mastered (MPS = 51.0–57.4). These findings reveal substantial gaps in conceptual understanding and quantitative application, highlighting the need for targeted instructional interventions, guided problem-solving, and enhanced conceptual discussions. The study provides empirical evidence to inform curriculum development and pedagogical strategies aimed at improving mastery in acid–base chemistry.