Standard enthalpies of zinc and copper methanesulfonate tetrahydrates formation

Abstract

Enthalpies of dissolution of zinc Zn(SO3CH3)2·4H2O and copper Сu(SO3CH3)2·4H2O methanesulfonate tetrahydrates in water were measured at 298.15 K by isoperibol solution calorimeter. Obtained values were recalculated to infinite dilution by Debay-Hukkel equations. There is a slight exothermic effect when the zinc salt dissolves (ΔsolHm0=−0.24±0.18 kJ/mol), while the copper salt is dissolved endothermically (ΔsolHm0=14.95±0.39 kJ/mol). Standard enthalpies of salts formation at 298.15 K were calculated on the basis of the experimental and literature data of ions formation in aqueous solutions by Hess Law. Corresponding values of standard enthalpies of formation are equal ΔfH298.150=−2667±9 kJ/mol and ΔfH298.150=−2464±9 kJ/mol for Zn(SO3CH3)2·4H2O and Сu(SO3CH3)2·4H2O, respectively.