Construing chemistry knowledge through structural formulas

This paper explores how structural formulas construe chemistry knowledge by examining their meaning-making. Based on types of structure and the register variable field in Systemic Functional Semiotics, it investigates the grammatical organization of structural formulas and the field-specific meanings they construe. The structural formulas examined in this study are the well-known Kekule formulas sourced from secondary school chemistry textbooks. The findings indicate that structural formulas are primarily organized around univariate and prosodic structures. In terms of field, the univariate structure realizes a breadth of compositional taxonomy, allowing for the representation of molecular compositions of varying complexities, and a spatial property of arrangements of atoms in space, making explicit a range of chemical knowledge of molecules, including molecular geometries, distribution of electron domains in a molecule, molecular properties and distinctions between isomers. In terms of prosodic structure, it construes a qualitative property of molecular polarity and a classificational taxonomy elucidating connections between atoms, enabling the representation of varying connectivity between different atoms in molecules. This study enriches the understanding of the meaning-making of structural formulas from a functional perspective.