Determinação experimental da solubilidade de ácido salicílico em soluções de etanol-água e propanol-água

Abstract

Salicylic acid, C7H6O3, is an organic acid of great importance in the production of aspirin, widely used in the food industry, pharmaceutical and in the biomedical area. Considering the such applicability of salicylic acid, this work focused on the study of the solubility of the acid in aqueous solutions of ethanol and propanol, with concentrations of 25%, 40%, 55% and 70% of alcohol, varying the temperature between 278, 2 K and 318, 2 K at constant atmospheric pressure. The gravimetric method was used to obtain the experimental data. The experimental procedure consisted of two equilibrium cells interconnected by a latex hose and connected to the thermostatic bath, salicylic acid was used in excess, the cells were in agitation for 2 hours followed with a rest period of 2 hours also, the samples were then sampled for further determination of solubility. The results obtained presented discrepancies with the literature and it can be concluded that the solubility of salicylic acid in hydro-alcoholic solutions increases with the increase of temperature, it can also be concluded that salicylic acid is more soluble in water and propanol solutions and less soluble in water and ethanol solutions.