APPARENT MOLAR VOLUMES AND VISCOSITIES OF SOME ALPHA-AMINO AND ALPHA,OMEGA-AMINO ACIDS IN AQUEOUS AMMONIUM-CHLORIDE SOLUTIONS AT 298.15-K

Apparent molar volumes and viscosity B coefficients of some α-, substituted α-, and α,ω-amino acids have been determined in water and aqueous ammonium chloride solutions at 298.15 K with a vibrating-tube digital density meter and a modified Cannon-Ubbelhode suspended-level viscometer. An increase in the volume of transfer of amino acids from water to aqueous ammonium chloride solutions and of viscosity B coefficients with increasing electrolyte concentration has been explained due to strong interactions of NH4+and Cl-with the charged centers of the zwitterions compared to ion-nonpolar-group interactions. The interactions have been rationalized in terms of the cosphere overlap model. © 1990, American Chemical Society. All rights reserved.