Calorimetric investigation of aqueous caffeine solutions and molecular association of caffeine

Abstract

Measurements of the enthalpy of solution of β-caffeine in water as a function of concentration at four temperatures are presented. Using our measurements of the heat capacity of solid β-caffeine we obtain the partial molar heat capacity of caffeine in solution. With the aid of osmotic coefficient measurements reported by other workers, the association constant and association enthalpy of caffeine are also calculated from the data measured.