Thermodynamic properties of aqueous diethanoloamine (DEA),N,N-dimethylethanolamine (DMEA),and their chloride salts:apparent molar heat capacities and volumes at temperatures from 283.15 to 328.15 k

摘要

Apparent molar heat capacities C_p. and apparent molar volumes V4, for aqueous diethanolamine (HOC_2H_4)_2NH. diethanolammonium chloride (HOC2H4 .NH~Cl . N.N’-dimethylethanolamine (HOC2H4)(CH3)2N, and N,N’-dimethylethanolammOniUm chloride (HOC2H4)(CH~ .NHCl were determined from 283.15 to 328.15 K with a Picker flow microcalorimeter and vibrating tube densimeter. The experimental results have been analyzed in terms of Young’s Rule with the Guggenheim form of the extended Debve—Htickel equation and appropriate corrections for chemical relaxation effects. These calculations lead to standard partial molar heat capacities and volumes for the neutral amines, (HOC2H4)2NH(aq) and (HOC2H4)(CH3)2N( aq . and the ions (HOC9H4)2NH2~(aq) and (H0C2H4)(CH3)2NH~(aq) over the experimental temperature range.