The spontaneity of chemical reactions: challenges with handling the concept and its implications

Abstract

Abstract The spontaneity concept plays crucial roles in the description of chemical reactions and entails a variety of implications, including the determination of the difference between galvanic and electrolytic cells. Students experience challenges with handling the concept and its implications within chemistry contexts. Everyday-life examples do not provide immediate evidence of chemistry-related spontaneity, and some features may be misinterpreted. The ΔG < 0 spontaneity criterion does not have an everyday-life correspondence and mostly remains abstract. Tendencies to equate exothermic or fast with spontaneous appear frequently. Using the spontaneity or non-spontaneity concepts in the interpretation of observed simple electrochemical phenomena may pose difficulties. The challenges are greatly enhanced by two diffuse contextual features: tendency to rote learning and inadequate language-mastery, with the latter being a major cause of the former and generally hindering conceptual understanding. The paper highlights the main difficulties diagnosed within an action research approach, documenting them with a sufficiently ample selection of illustrative examples. The ways in which diagnoses are utilised as guidelines for in-class interventions aimed at addressing identified challenges are delineated and discussed. The integration of chemistry-concepts analysis and language-analysis is viewed as the most powerful instrument to address identified difficulties in real time.