scholarly journals Alternative estimations of the first hydrolysis constant of tetravalent plutonium

2011 ◽  
Vol 288 (1) ◽  
pp. 89-92 ◽  
Author(s):  
G. L. Silver
Keyword(s):  
Hydrolysis Constant

Thermodynamic parameters for the complexation of Tc(IV) with bromide under aqueous conditions

2020 ◽  
Vol 108 (5) ◽  
pp. 409-414
Author(s):  
Cecilia Eiroa-Lledo ◽  
Donald E. Wall ◽  
Nathalie A. Wall
Keyword(s):  
Working Conditions ◽  
Equilibrium Constants ◽  
Liquid Extraction ◽  
Complexation Reaction ◽  
Hydrolysis Constant ◽  
Carboxylate Ligands ◽  
Liquid Liquid Extraction ◽  
Varied Temperature ◽  
Aqueous Conditions ◽  
Aqueous Complexes

AbstractTechnetium-99 is a long-lived fission product present in nuclear wastes, found mainly as Tc(VII) and Tc(IV) in the environment. The quantification of the equilibrium constants for the formation of Tc(IV) aqueous complexes has been limited to carboxylate ligands and interactions with the halides is mostly unknown. This work reports equilibrium constants of the formation of the TcO(OH)+ complexes with Br−, in a 3 M NaClO4 solution of pcH 2 and varied temperature, using a liquid-liquid extraction system. Neutron activation confirmed the suitability of the extraction technique for this work. Under the working conditions, Br− forms a weak exothermic TcO(OH)Br complex, with a Gibbs free energy (ΔGr) of 3 ± 3 kJ · mol−1 at a temperature of 273.15 K. The values for ΔHr (−32 ± 3 kJ · mol−1) and ΔSr (106 ± 9 J · mol−1 · K−1) of the complexation reaction were quantified using a van’t Hoff analysis. This work also showed that bromide addition does not displace the hydroxide from TcO(OH)+, as the equilibrium constant of bromide addition is much weaker than the first hydrolysis constant of the metal.

First Hydrolysis Constant of Lutetium (III) by Solvent Extraction

2007 ◽  
Vol 36 (8) ◽  
pp. 1063-1071 ◽  
Author(s):  
J. Ramírez-García ◽  
M. Jiménez-Reyes ◽  
M. Solache-Ríos ◽  
A. Rojas-Hernández
Keyword(s):  
Solvent Extraction ◽  
Hydrolysis Constant

scholarly journals THE SULFONIUM SALT OF MUSTARD GAS: BIS-ß-[BIS(ß-HYDROXYETHYL) SULFONIUM] ETHYLSULFIDE DICHLORIDE (H·2TDG)

1947 ◽  
Vol 30 (6) ◽  
pp. 457-464 ◽  
Author(s):  
Roger M. Herriott
Keyword(s):  
Activation Energy ◽  
Temperature Coefficient ◽  
Arrhenius Equation ◽  
Effect Of Temperature ◽  
Mustard Gas ◽  
Hydrolysis Constant ◽  
Dilute Solutions ◽  
Sulfonium Salt ◽  
Simple Method

1. The sulfonium salt H·2TDG is formed when H is mixed with even dilute solutions of TDG. Crystalline H·2TDG was isolated from such a reaction mixture. A simple method of preparation of this salt is outlined. 2. A material which differs from H·2TDG in that it hydrolyzes faster, is formed when H hydrolyzes in water. This material is probably H·1TDG but it was not isolated. Approximately 5 to 8 per cent of the original H is converted to this sulfonium salt. 3. The hydrolysis constant of M/100 H·2TDG has been determined at 20°, 25.5°, 37°, 75°, and 100°C., a temperature coefficient, Q10, of 3–4 was obtained. The effect of temperature is in agreement with that predicted by the Arrhenius equation. An activation energy of 26,000 calories was calculated.

scholarly journals Complexation parameters for the actinides(IV)-humic acid system: a search for consistency and application to laboratory and field observations

2008 ◽  
Vol 96 (6) ◽  
Author(s):  
Pascal E. Reiller ◽  
Nick D. M. Evans ◽  
Gyula Szabó
Keyword(s):  
Original Data ◽  
Formation Constants ◽  
Field Observations ◽  
Independent Data ◽  
Acid System ◽  
Hydrolysis Constant ◽  
Independent Laboratory ◽  
System A ◽  
Hydrolysis Of ◽  
Full Analogy

SummaryThe coherence of actinide(IV) complexation by humic substances (HS) is reviewed and new data are proposed. In a first attempt, the values of independent data from literature on Th(IV), U(IV), and Pu(IV) are collected, selected, and compiled. The data obtained follow the “classical” trend of increasing conditional formation “constants” with pH, led both by the increasing ionisation of HS and by the extensive hydrolysis of the tetravalent actinides. Even though a fair agreement is evident, the experimental uncertainties do not permit a full analogy between the actinides(IV) to be ascertained. In a second attempt, the experiments from which the original data are available were reinterpreted using only one hydrolysis constant set for U(IV) as an example, considering that all actinides(IV) have analogous humic complexation behaviour. Hence, the obtained evolution of conditional formation “constants” is much more coherent and the uncertainties do not permit to distinguish an actinide(IV) from one another. The obtained data are then applied to independent laboratory and

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