Dissolution properties of ammonium dipicrylamide in dimethyl sulfoxide and N-methyl pyrrolidone

Abstract The enthalpies of dissolution for ammonium dipicrylamide (ADPA) in dimethyl sulfoxide (DMSO) and N -methyl pyrrolidone (NMP) were measured using a RD496-2000 Calvet microcalorimeter at 298.15 K under atmospheric pressure. Empirical formulae for the calculation of the enthalpies of dissolution (Δ diss H ) were obtained from the experimental data of the dissolution processes of ADPA in DMSO and NMP. The linear relationships between the rate ( k ) and the molality ( b ) were found. The corresponding kinetic equations describing the two dissolution processes were d α / d t = 10 − 2.38 ( 1 − α ) 0.86 for the dissolution of ADPA in DMSO, and d α / d t = 10 − 2.49 ( 1 − α ) 0.83 for the dissolution of ADPA in NMP, respectively.