Energy volume coefficient of solutions involving amides, H₂O and D₂O at 298.15 K

904-913Sound velocities at 298.15 K and densities at different temperatures of aqueous solutions of amides (formamide, acetamide, propionamide, DMF and DMAC) have been measured in the concentration range ~0.2 to 2.0 m. The experimental data have been used to calculate the thermodynamic parameters like apparent molar volume (ϕv), apparent molar isothermal compressibility (ϕKT) of solutes at various concentrations and energy volume coefficient (dU/dV)T of solutions at different amide concentrations in H2O as well as in D2O solutions. From the infinite dilution properties (ϕv0 and ϕKT 0, the transfer volumes and transfer compressibilities for the transfer of amides from H2O to D2O solvent system have been calculated. The variation of energy volume coefficient in H2O and D2O systems and the trends in limiting transfer properties are examined and have been interpreted in terms of effects of amides on the water structure through H-bonding and hydrophobic interactions