Heats of dilution and related thermodynamic properties of aqueous neodymium chloride and erbium chloride solutions

Date
1956
Authors
Naumann, Alfred
Major Professor
Advisor
Committee Member
Journal Title
Journal ISSN
Volume Title
Publisher
Altmetrics
Authors
Research Projects
Organizational Units
Chemistry
Organizational Unit
Journal Issue
Series
Department
Chemistry
Abstract

A differential calorimeter has been constructed to measure the heats of dilution of electrolytic solutions. The differential method made possible the determination of heats of dilution to within a few thousands of a calorie. Precision of this order was necessary to obtain meaningful values for the thermodynamic properties of very dilute solutions;The heats of dilution of neodymium chloride and erbium chloride solutions have been measured at 25°C for concentrations up to 0.2 molal. Empirical expressions for the relative apparent molal heat content of the solute, &phis; L; the relative partial molal heat content of the solvent, L¯1; and the relative partial molal heat content of the solute, L¯2, have been derived from the heats of dilution. The following equations have been derived for neodymium chloride solutions: fL=6925 m1/2-16725 m+22278m3/2 -7596m2, 74 L1&d1;= -62.37m 3/2+301.32m2 -602.04m5/2+273.70 m3 ,80 L2&d1;=10387 m1/2-33450 m+55695m 3/2+22788 m2. 79 The corresponding equations for erbium chloride solutions were as follows: fL=5687 m1/2-8637m +7066m3/2, 87 L1&d1;=-51.2 3m3/2+155.60 m2-190.95 m5/2, 88 L2&d1;=8531 m1/2-17274 m+17665m 3/2. 89;The thermodynamic properties of neodymium chloride and erbium chloride solutions were the same, within experimental error, for concentrations above 0.02 molal. For concentrations below 4 x 10-4 molal, the thermodynamic properties of neodymium chloride solutions followed the Debye-Huckel law predictions, but the thermodynamic properties of erbium chloride solutions appeared to depart from theoretical predictions.

Comments
Description
Keywords
Citation
Source