Purification and Properties of Disodium Salt of Ethylenediaminetetraacetic Acid as Primary Standard

Abstract

The perchloric acid was fumed for 5 minutes and the permanganate trap brought to boiling. The two vessels were heated for 10 minutes further after which time the current of air was discontinued and water baths initially at 85°C. were placed about the receivers for 15 minutes. The receiving solutions were transferred to a 50ml. volumetric flask; 1 to 1 ethyl alcohol-hydrochloric acid was used for rinsing and making up to volume. The resulting solution was filtered through a large Whatman's No. 42 filter paper into the transmittancy cell. A solution of 1 to 1 ethyl alcoholhydrochloric acid was used as a blank solution.Samples distilled into 3% hydrogen peroxide in the manner described previously, then distilled into thiourea from the peroxide solution to which 5 ml. of concentrated sulfuric acid were added, gave results in agreement with the standard curve.A standard curve was prepared by distilling aliquots of the ruthenium solution from perchloric acid. LITERATURE CITED(1)

Spin-orbit coupling and magnetic field effects in photoredox reactions of ruthenium(II) complexes

“…Similarly, the fitted TST-Eckart curve was also found to be lower than the data points of Anastasi5 based on the rate of disappearance of methyl radicals, which, however, have been shown to be subject to substantial error due to the omission of other potential CH3 loss reactions. 25 Our success in modeling the experimental data suggests that it is not necessary to appeal to an additional high-temperature reaction channel in order to explain the non-Arrhenius behavior. This is a reassuring conclusion, since the other likely candidate, CH3 + CH20 -CH3CHO + H, involves a much tighter transition state and was shown by kinetic modeling to be unimportant (25) The results of our recent kinetic modeling of Anastasi's first-order CH3 decay rate constants (ref 5) show that the omission of the secondary reactions involving CH3 and CHO radicals erroneously increases the values of kj by a factor of 2-3.…”

“…25 Our success in modeling the experimental data suggests that it is not necessary to appeal to an additional high-temperature reaction channel in order to explain the non-Arrhenius behavior. This is a reassuring conclusion, since the other likely candidate, CH3 + CH20 -CH3CHO + H, involves a much tighter transition state and was shown by kinetic modeling to be unimportant (25) The results of our recent kinetic modeling of Anastasi's first-order CH3 decay rate constants (ref 5) show that the omission of the secondary reactions involving CH3 and CHO radicals erroneously increases the values of kj by a factor of 2-3. The inclusion of these reactions led to much lower values as shown in Figure 4.…”

Nuclear Magnetic Resonance Technique for Determining Hydration Numbers

“…Disodium (ethylenedinitrilo)tetraacetatedihydrate, Na2H2EDTA-2H20 (Compound A), was obtained from J. T. Baker Chemical Co. (Assay 99.7%) and was used as received. In addition, an ultrapure sample (Compound B) was prepared according to the recommended procedure (1). The molybdenum (VI) complex of V-methyliminodiacetic acid was prepared recently (3) and was shown to have the composition Na^oOsMIDA 4H20 (Compound C).…”

Continuous Titrations with a Tubular Mercury-EDTA Electrode.

“…Subsequently, U (VI) is determined by controlled-potential coulometric titration in 0.5.1/ H2S04. Booman and Holbrook (2) investigated other procedures for extracting U(VI) and titrating it coulometrically. Verbeek, Moelwyn-Hughes, and Verdier (11) describe a polarographic method for U(VI) that can tolerate excess Fe(III); the supporting medium is neutral 0.75.1/ NaF.…”