Aqueous Guanidinium Salts: Part I. Densities, Ultrasonic Velocities, and Apparent Molar Properties

The densities and ultrasonic velocities in aqueous solutions of guanidinium chloride, bromide, acetate, perchlorate and sulfate have been measured at 25°C. The infinite dilution partial molar volumes and compressibilities of the salts were estimated and analyzed by the Pitzer equations. The concentration dependence of densities and sound velocities of the guanidinium salts can be correlated by the Pitzer equations with an average root-mean-square deviation of 0.025 kg-m^-3 and 0.31 m-s^-1, respectively.