Spectrophotometric study of competitive complexation equilibria involving overlapped spectral responding species: Determination of the stability constant of bismuth-pyrophosphate complex

AbstractSpectrophotometric study of competitive complex formation equilibria involving overlapped spectral responding species applying a simple and versatile algorithm was carried out. The algorithm involves multivariable regression for calculation of equilibrium concentrations from multiwavelength data and mass action law for the stability constant calculation. The used regression functions are part of common statistical software. Stability constants and complex stoichiometry of competing equilibria were simultaneously determined. The species concentration profiles at several spectral overlapping and α-coefficient of competing reaction were obtained. Non-absorbing bismuth — pyrophosphate (PPh) system was studied as a competitive reaction of bismuth — 4-(2-Pyridylazo) resorcinol (PAR) complex. The formation of Bi-PPh complex with 1:1 stoichiometry was proved in the studied concentration region (CBi = 1×10−5 mol L−1; CPPh = 5×10−6 − 1×10−4 mol L−1). The stability constant of the complex at pH 1 and µ = 1.0 have been determined: logβ = 4.2±0.2.

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Spectrophotometric Study of The Stability Constant of Complexation of Metolazone Metal Ions

Journal of Chemistry and Chemical Sciences ◽

10.29055/jccs/559 ◽

2018 ◽

Vol 8 (1) ◽

pp. 75-78

Author(s):

Jaishri Kaushik ◽

Archana Shukla

Keyword(s):

Stability Constant ◽

Metal Ions ◽

Spectrophotometric Study ◽

The Stability

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A model of carbon dioxide dissolution and mineral carbonation kinetics

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2009.0349 ◽

2009 ◽

Vol 466 (2117) ◽

pp. 1265-1290 ◽

Cited By ~ 31

Author(s):

Mark J. Mitchell ◽

Oliver E. Jensen ◽

K. Andrew Cliffe ◽

M. Mercedes Maroto-Valer

Keyword(s):

Carbon Dioxide ◽

Mass Action ◽

Mineral Carbonation ◽

Leading Order ◽

Full System ◽

Mass Action Law ◽

Gaseous Carbon Dioxide ◽

Equilibrium Concentrations ◽

Kinetics Of ◽

Independent Parameters

The kinetics of the dissolution of carbon dioxide in water and subsequent chemical reactions through to the formation of calcium carbonate, a system of reactions integral to carbon sequestration and anthropogenic ocean acidification, is mathematically modelled using the mass action law. This group of reactions is expressed as a system of five coupled nonlinear ordinary differential equations, with 14 independent parameters. The evolution of this system to equilibrium at 25 ° C and 1 atm, following an instantaneous injection of gaseous carbon dioxide, is simulated. An asymptotic analysis captures the leading-order behaviour of the system over six disparate time scales, yielding expressions for all species in each time scale. These approximations show excellent agreement with simulations of the full system, and give remarkably simple formulae for the equilibrium concentrations.

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Does a stability constant decide on a repository permit?

10.5194/egusphere-egu21-1502 ◽

2021 ◽

Author(s):

Theresa Hennig ◽

Michael Kühn

Keyword(s):

Stability Constant ◽

Clay Minerals ◽

Stability Constants ◽

Nuclear Waste ◽

Host Rock ◽

Mass Action ◽

Opalinus Clay ◽

Diffusive Transport ◽

Predominant Species ◽

The Stability

Safety of a nuclear waste repository is based to a large extent on the isolation of the radioactive waste within a suitable host rock. Clay rocks provide an option due to their very low hydraulic conductivity only allowing diffusive transport. Diffusion processes in clay formations are complex due to the diffuse double layers (DDL) enveloping the clay minerals to compensate their net surface charge and the associated different migration behaviour for cationic, anionic and neutral species. Therefore, determination of the speciation of an element in the porewater is essential to quantify migration lengths precisely. Safety assessments are based on numerical simulations to cover time periods of up to one million years and thus the predominant species of a radionuclide, dependent on the stability constants within the law of mass action, might be signififcant.In the present study, we use uranium, one of the main components in spent fuel, as an example for the diffusion in the Swiss Opalinus Clay, a potential host rock for the storage of nuclear waste. In the geochemical system, uranium is mainly present as U(VI) in ternary uranyl complexes with calcium and carbonate, whereby speciation depends on the selected thermodynamic data (Hennig et al., 2020). For instance, the stability constants for the neutral uranyl complex Ca2UO2(CO3)3 differ slightly in literature. Depending on the selected one, either the neutral or the anionic complex CaUO2(CO3)32- is the predominant species in the system with an associated varying interaction with the DDL of the clay minerals. With our one-dimensional, multi-component diffusion models we quantified the effect of the selected stability constant on the diffusion length for the host rock scale.The chemistry in the porewater of the three facies of the Opalinus Clay, shaly, sandy and carbonate-rich, plays a key role for the sorption processes (Hennig et al., 2020) as well as for the composition and thickness of the DDL and therewith the diffusive transport. Based on our results, we show, that the influence of the predominant uranium species on the migration lengths varies between the individual facies, but is overall negligible for the host rock scale. Consequently, a stability constant is not decisive for the required thickness of the host rock as geological barrier.&#160;Hennig, T.; Stockmann, M.; K&#252;hn, M. Simulation of diffusive uranium transport and sorption processes in the Opalinus Clay. Applied Geochemistry 2020, 123. doi:10.1016/j.apgeochem.2020.104777.

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Studies on Activator Formation in Human Plasma with Streptokinase

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649088 ◽

1973 ◽

Vol 30 (02) ◽

pp. 381-392

Author(s):

M Martin ◽

Keyword(s):

Human Plasma ◽

Plasminogen Activator ◽

Mass Action ◽

Activator Concentration ◽

Kinetic Effect ◽

Mass Action Law

SummaryThe plasminogen-streptokinase complex called “activator” was present in diluted plasma in the form of a largely dissociated mixture. More than ⅞ of the streptokinase and plasminogen molecules were available for further activator formation.The activator is probably a dissociated complex of the formulaStreptokinase + Plasminogen ⇄ Activator.The fact that an increase in activator concentration by x times is obtained by multiplying either the streptokinase content by the factor y or the plasminogen concentration by the same factor y would point to a kinetic effect along the lines of the mass action law.

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Synthesis and solvatochromic studies of 2- amino-3-phenolazo1-(4-sulfophenyl)-3-methyi-5-pyrozolone and use it for the determination of trace amount of Nickel (II) in blood samples

International Journal of Bioassays ◽

10.21746/ijbio.2016.10.001 ◽

2016 ◽

Vol 5 (10) ◽

pp. 4920

Author(s):

Amar M. Ali ◽

Hussain. J. Mohammed*

Keyword(s):

Stability Constant ◽

Trace Amount ◽

Benzenesulfonic Acid ◽

Determination Method ◽

Blood Samples ◽

Determination Of Nickel ◽

Normal Human ◽

The Stability ◽

Normal Human Blood

A new, simple, sensitive and rapid spectrophotometric method is proposed for the determination of trace amount of Nickel (II). The method is based on the formation of a 1:2 complex with 4-(4-((2-hydroxy-6-nitrophenyl) diazenyl) -3-methyl-5-oxo-2, 5-dihydro-1H-pyrazol-1-yl) benzenesulfonic acid (2-ANASP) as a new reagent is developed. The complex has a maximum absorption at 516 nm and εmax of 1. 84 X 105 L. mol-1. cm-1. A linear correlation (0. 25 – 4. 0μg. ml-1) was found between absorbance at λmax and concentration. The accuracy and reproducibility of the determination method for various known amounts of Nickel (II) were tested. The results obtained are both precise (RSD was 1. 2 %) and accurate (relative error was 0. 787 %). The effect of diverse ions on the determination of Nickel (II) to investigate the selectivity of the method were also studied. The stability constant of the product was 0. 399 X 106 L. mol-1. The proposed method was successfully applied to the analysis of diabetes blood and normal human blood.

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Transition states and entangled mass action law

Results in Physics ◽

10.1016/j.rinp.2021.103922 ◽

2021 ◽

Vol 22 ◽

pp. 103922

Author(s):

A.N. Gorban

Keyword(s):

Transition States ◽

Mass Action ◽

Mass Action Law

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N-ACYL SUBSTITUTED PHENYLHYDROXYLAMINES: THE EFFECT OF RADICAL CHANGE ON ANALYTICAL BEHAVIOR

Canadian Journal of Chemistry ◽

10.1139/v57-192 ◽

1957 ◽

Vol 35 (12) ◽

pp. 1454-1460 ◽

Cited By ~ 18

Author(s):

C. A. Armour ◽

D. E. Ryan

Keyword(s):

Aqueous Solution ◽

Stability Constant ◽

Radical Change ◽

Spectrophotometric Study ◽

Iron Complex ◽

Membered Ring ◽

Analytical Reagents ◽

Colorimetric Reagent ◽

Analytical Behavior

The synthesis of a number of N-acyl substituted phenylhydroxylamines is outlined and the effect of the change in the nature of the acyl group on their usefulness as analytical reagents is described. Stability constant measurements in alcohol show an increase in stability with an increase in basicity of reagent regardless of the nature of the attached group; their ability to precipitate complexes from aqueous solution, however, is markedly dependent on the nature of the attached radical. A spectrophotometric study shows the existence of both a 1:1 and a 1:3 iron complex. A more sensitive colorimetric reagent results with an unsaturated five-membered ring as the attached grouping.

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