Thermodynamics of complexation of aqueous 18-crown-6 with barium ion:apparent molar volumes and apparent molar heat capacities of aqueous(18-crown-6 + barium nitrate)at temperatures(278.15 to 393.15)K,at molalities(0.02 to 0.33)mol centre dot kg~(-1)

摘要

We have measured the densities at T -(278.15 to 368.15)K and heat capacities at T=(278.15 to 393.15)K of aqueous solutions of {18-crown-6 + Ba(NO_3)_2} at molalities m=(0.02 to 0.33)mol centre dot kg~(-1)and at the pressure 0.35 MPa.We have applied Young's rule and have accounted for chemical speciation and relaxation effects to resolve V_phi and C_(p,phi),to include contributions of the 18-crown-6-Ba2+(aq)complex in the mixture.We have also calculated estimates of the change in volume DELTA_rV_m,the change in heat capacity DELTA_rC_(p,m),the change in enthalpy DELTA_rH_m,and the equilibrium quotient lg Q for formation of the complex at T=(278.15 to 393.15)K and m=(0 to 0.33)mol centre dot kg~(-1)in the mixture.