The Heat Capacities and Heat Contents of Solutions of Cerium and Neodymium Chlorides at 25°

Enthalpies of Dilution of NdCl3(aq) at Temperatures from 297.89 K to 372.08 K and an Extended Pitzer Ion-Interaction Model for the NdCl3 + H2O System

“…Enthalpies of Dilution. The enthalpies of dilution Δ dil H m of NdCl 3 (aq) at 298.15 K and a pressure of ≈0.1 MPa have been given in three reports from Spedding's laboratory. ,, These Δ dil H m measurements were made from 0.000 066 mol·kg -1 to 0.1879 mol·kg -1 , and from 0.000 97 mol·kg -1 to 3.929 mol·kg -1 , using adiabatic dilution calorimetry. The enthalpies of dilution from these two studies agreed well, with an average absolute difference of only ≈0.025 kJ·mol -1 between the two sets in the region of overlap.…”

“…Finally, the value calculated from additivity, discussed previously, is also shown. The measurement apparatus used by Spedding and Jones 8 should have been capable of greater accuracy than the apparatus of Spedding and Miller, which suggests that most of this skewing comes from experimental errors in the Spedding and Miller J φ values. Clearly, Spedding and Miller's values lead to a too negative , and we consider them no further.…”

“…Several sets of thermodynamic data at 298.15 K from Spedding's laboratory extend from low molalities to the saturated solutions: isopiestic vapor pressures, , enthalpies of dilution, heat capacities, and densities/apparent molar volumes . In addition, they reported measurements at lower molalities of the emf's of concentration cells with transference for NdCl 3 (aq), , enthalpies of dilution, densities/partial molar volumes, and also enthalpies of solution of NdCl 3 (cr) and NdCl 3 ·6H 2 O(cr) in water. ,, Their only thermodynamic study of NdCl 3 (aq) at other temperatures is of the densities/apparent molar volumes at temperatures from 278.206 K to 352.891 K . A few thermodynamic studies for NdCl 3 (aq) have been reported at other laboratories: isopiestic measurements at 298.15 K , and 293.15 K, emf measurements for concentration cells with transport at 293.15 K, and enthalpies of solution of NdCl 3 (cr) in water at 298.15 K and for the temperature range (287.95 to 365.99) K…”

Relative apparent molal heat contents of some rare-earth chlorides and nitrates in aqueous solutions

“…predictions is usually made on a combination of equations (22) and (ill). The Debye-Huckel expression for the rational activity coefficient is given by equation 2 Since ( 00 ) = 0, B = 0, and -Kr A 5 --.…”

Some physical and chemical properties of scandium and the rare earths

“…Calorimetric measurements of heats of solution of rareearth metals and salts in water and hydrochloric acid were carried out by Miller (13,14), Flynn (15» 16), Naumann (17), and Eberts (18).…”