Effect of temperature on the partial molar volumes of some bivalent transition metal nitrates and magnesium nitrate in the water-rich region of binary aqueous mixtures of dimethyl acetamide

Abstract

Partial molar volumes of some bivalent transition metal nitrates, viz., manganese nitrate, cobalt nitrate, nickel nitrate, copper nitrate, zinc nitrate and magnesium nitrate have been determined in binary aqueous mixtures of N,N-dimethylacetamide (DMA) in the water-rich region (5, 10, 15, 20 and 25% by weight) of DMA from solution density measurements at 303.15 K, and in 5% <i style="">w/w</i> DMA + H₂O at five equidistant temperatures (298.15, 303.15, 308.15, 313.15 and 318.15 K). The density data have been analysed by Masson’s equation. The partial molar volumes and experimental slopes have been interpreted in terms of ion-solvent and ion-ion interactions, respectively. The partial molar volumes vary with temperature as a power series of temperature. Structure making/breaking capacities of electrolytes have been inferred from the sign of the second derivative of partial molar volumes with respect to temperature at constant pressure. All the electrolytes have been found to act as structure breakers in binary aqueous mixtures of dimethyl acetamide.