I. The Magnetic Susceptibility of Europium(III) and Europium(II) Ions and the Photochemical Reduction of Water by Europium(II) Ion. II. The Magnetic Susceptibility of Europium and Samarian Amalgams. III. Observations on the Chemistry of Europium. IV. Age Determination from Carbon-14 Content: Ionization Chamber Techniques. V. The Volume Change Due to Hydrogen Bonding of Methanol in Carbontetrachloride Solution

Author: Douglas, David Lewis

Year: 1951

Degree: Dissertation (Ph.D.)

Advisor: Yost, Don M.

Committee Member: Unknown, Unknown

Option: Chemistry; Physics

DOI: 10.7907/9X7A-Y940

Abstract

The discovery of the photchemical reduction of water by europium(II) ion is reported. By use of a chemical actinometer for determining light intensities and a Gouy balance for following the change in magnetic susceptibility overall quantum yields were determined to be about 0.2 for solutions 0.5 m. in HCl and 0.15 m. in EuCl2. A mechanism consistent with the experimental data is

Eu(II)·H2O + hv = Eu(II)*·H2O

Eu(II)*·H2O = Eu(III)aq + H + OH-aq

H + H+aq + Eu(II)aq = Eu(III)aq + H2

The thermal reaction under these conditions was found to be relatively unimportant.

The magnetic susceptibility of europium in its liquid amalgam was observed to be 8.09 ± 0.03 Bohr magnetons and that of samarium in its liquid amalgam to be 2.31 ± 0.05 Bohr magnetons.

In a brief investigation europium(II) perchlorate was observed to be quite soluble in water and the solution stable as regards oxidation of the europium. The preparation of europium(II) carbonate is discussed. The possible reduction of CO2 by the hydrogen atoms produced in the irradiation of Eu(II) solutions was investigated, negative results being obtained.

Using an ionization chamber in conjunction with a very sensitive quartz fiber electroscope, the small amount of C14 present in "living" carbon was detected. The problem of background ionization observed in the chambers was investigated in detail. Preliminary experiments to determine the suitability of the instruments for the measurement of the age of archeological specimens were carried out. The age of one specimen was observed to be about 3,500 years.

The densities of dilute solutions of CH3OH in CC14 are reported. A comparison of the partial molar volumes obtained therefrom with the mono­mer fraction of CH3OH determined by spectroscopic means leads to the conclusion that the average volume of the monomer is only 2% greater than that of the CH3OH in the polymers.

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