APPARENT AND PARTIAL MOLAL HEAT CAPACITIES OF SOME AQUEOUS RARE EARTH NITRATES AND PERCHLORATES FROM TENTH MOLAL TO SATURATION AT 25℃

摘要

The specific heat capacities of aqueous solutions of Pr(N03)3, Sm(N03)3, Tb(N03)3, Dy(N03)3, Ho(NO3)3, Tm(NO3)3, Yo(N03)3, Pr(C1O4)3, Sm(C104)3, Tb(ClO4)3, Dy(ClO4)3, HO(ClO4)3, Er(ClO4)3, Tm(ClO4)3, and Yb(ClO4)3 were measured over the concentration range of 0.1 molal to saturation at 25°C. Apparent molal heat capacities, Φcp , for each salt were calculated from the specific heat capacities. Empirical polynomial equations obtained with the aid of the computer were used to expressΦcp as a function of m1/2 . The partial molal heat capacities of the solvent, Cp1 and of the solute, Cp2 were calculated from these equations. The $ data for the rare earth perchlorate solutions indicate that the rare earths as they exist in solution are divided into two series.