Abstract

A new isothermal titration calorimeter has been designed to facilitate the study of heats of reaction and heats of solution at constant temperature. With this calorimeter, endothermic or exothermic processes can be studied at temperatures constant to ±0.0002°C. Heat effects are compensated by balancing the heat effect of the process taking place in the calorimeter against a variable heat and a constant cooling Peltier device. The calorimeter was tested by measuring the heat of ionization of water and the heat of dilution of aqueous HClO_4 solutions. For these systems heats were measured to an accuracy of ±0.02 calorie. Log K, ΔH°, ΔS° and ΔCp° values valid at zero ionic strength have been reported for the interaction of CN^- with Ni^2+ , Zn^2+ , Cd^2+ and Hg^2+ in aqueous solution at 10, 25 and 40°C. The results were compared to electrostatic predictions and it was found that electrostatic considerations do not predict the metal-ligand behavior in solution. The effect of temperature upon the behavior of ΔG, ΔH and ΔS is predicted using the ΔCp values determined in this study. Log K, ΔH°, ΔS° and ΔCp° values were determined for the glycinate complexes of bivalent Mn, Fe, Co, Ni, Cu, Zn and Cd. The results indicate that solvent effects for the various metal complexes are similar (based on ΔCp values) and that the temperature dependence of the thermodynamics of the metal glycinate complexes are similar for each of the metal glycinate systems.

Degree

PhD

College and Department

Chemistry and Biochemistry

Rights

http://lib.byu.edu/about/copyright/

Date Submitted

1968-08-01

Document Type

Dissertation

Handle

http://hdl.lib.byu.edu/1877/Letd593

Keywords

Metals, Thermodynamics, Heat of solution, Solution (Chemistry)

Language

English

Share

COinS