Thermochemistry of transfer of copper(II) nitrate from water to aqueous methanol and 2-propanol

The calorimetric enthalpies of mixing at 25°C of aqueous solutions of copper(II) nitrate (m 0 = 4.62 mol/kg solvent) with aqueous methanol (over the whole range of compositions) and aqueous 2-propanol (for alcohol mole fractions no more than 0.5) have been determined. These values were used to calculate the standard enthalpies of transfer of copper(II) nitrate from water to water-alcohol mixtures. A comparative analysis of the enthalpies of transfer from water to aqueous methanol has been carried out for copper(II) nitrate and copper(II) chloride based on our data and the related literature. Chloride ions start entering the nearest neighborhood of a copper(II) ion in aqueous methanol when the alcohol mole fraction is 0.6. The enthalpies of transfer of Cu(NO 3 ) 2 from water to aqueous 2-propanol have been found to correlate with the optical densities of these solutions.