CRYOSCOPIC BEHAVIOR IN THE BINARY MIXTURES OF ACETAMIDE-SODIUM ACETATE AND ACETAMIDE-SODIUM ACETATE TRIHYDRATE

摘要

The melting point depression of acetamide on addition of anhydrous sodium acetate and sodium acetate trihydrate was followed by DSC. Two sets of measurements were made for two crystalline forms in which the melts crystallized. From cryoscopic data, activity coefficients of acetamide were calculated in the concentration range 0 to 0.390 mole fraction of sodium acetate and 0 to 0.376 mole fraction of sodium acetate trihydrate. Activities of the salt components were calculated from the activities of the solvent using a simple analytical method. From melting point depression data and the known molar cryoscopic constant of acetamide, the Van't Hoff dissociation factor was calculated for both anhydrous and hydrated sodium acetate in the concentration ranges studied. [References: 16]