Determination of the Avogadro Constant via Stearic Acid Monolayer Formation

This investigation explores the determination of the Avogadro constant by forming a stearic acid monolayer using a 0.16 g/L hexane solution. The methodology involves pipette calibration, monolayer surface area measurement, and the application of the cosine theorem to calculate molecular dimensions based on bond lengths and angles from the IB data booklet.

The author compares results derived from a self-calculated cylinder model against Langmuir's accepted values, finding that the latter yields a more accurate constant (5.767 × 10²³ mol⁻¹) with a 4.23% error. This exemplar is distinguished by its detailed geometric analysis of molecular structure and a critical evaluation of the limitations of simplified geometric modeling in chemical calculations.