Activity coefficient assumptions in the determination of the association constant of thallous chloride

1964 ◽  
Vol 17 (5) ◽  
pp. 522 ◽  
Author(s):  
JB Macaskill ◽  
MH Panckhurst
Keyword(s):  
Sodium Chloride ◽  
Ionic Strength ◽  
Activity Coefficient ◽  
Association Constant ◽  
Specific Interaction ◽  
Sodium Perchlorate ◽  
Ionic Activity ◽  
Different Types

The solubility of thallous chloride has been measured in sodium chloride and sodium perchlorate solutions at an ionic strength less than 0 1M. The association constant of thallous chloride has been determined from these measurements using two different types of ionic activity coefficient expression, one of them incorporating Br�nsted's principle of specific interaction. The method for determining the association constant gives all the parameters in the treatment but the two activity coefficient expressions give different sets of parameters. These are discussed.

Activity coefficient assumptions m the determination of the association constant of thallons chloride. II. Effect of interactions between freeions

1966 ◽  
Vol 19 (6) ◽  
pp. 915 ◽  
Author(s):  
JB Macaskill ◽  
MH Panckhurst
Keyword(s):  
Sodium Chloride ◽  
Activity Coefficient ◽  
Association Constant ◽  
Sodium Perchlorate ◽  
Barium Chloride ◽  
Specific Interactions ◽  
Ionic Activity ◽  
Caesium Chloride ◽  
Free Ions

The solubility of thallous chloride has been measured in solutions of hydrochloric acid, caesium chloride, caesium perchlorate, barium chloride, and in various mixtures of sodium chloride and sodium perchlorate. These measurements are analysed to give the association constant for thallous chloride, paying particular attention to ionic activity coefficient formulae. It is shown that an activity coefficient expression which assumes no specific interactions between free ions is unsatisfactory in contrast to an expression which assumes such interactions. The consequences of this are discussed.

Activity coefficient assumptions in the determination of the association constant of thallium(I) chloride. III. Effects of other association reactions

1967 ◽  
Vol 20 (12) ◽  
pp. 2633 ◽  
Author(s):  
KH Khoo ◽  
MH Panckhurst
Keyword(s):  
Activity Coefficient ◽  
Sodium Acetate ◽  
Association Constant ◽  
Specific Interaction ◽  
Mixed Solvents ◽  
Sodium Perchlorate ◽  
Barium Chloride ◽  
Interaction Coefficients ◽  
Free Ions

Measurements are reported of the solubility of thallium(I) chloride in aqueous solutions of sodium acetate and thallium(I) perchlorate and in solutions of sodium chloride, barium chloride, and sodium perchlorate in 16.7, 30, and 60 wt. % methanol-water mixtures. The measurements in water are used to test the merits of two types of ionic activity coefficient expression. It is shown that it is necessary to take account of specific interactions between free ions and that this also allows for small amounts of other association reactions in the same solution. The possibility of allowing for subsidiary association without using specific interaction coefficients is discussed, and it is concluded that this cannot be done in a completely satisfactory way. Measurements in mixed solvents are used to determine association parameters for the complex TlCl.

Activity coefficient assumptions in the determination of association constants. V. Association of thallium(I) bromide from solubility measurements

1969 ◽  
Vol 22 (5) ◽  
pp. 911 ◽  
Author(s):  
CW Childs ◽  
MH Panckhurst
Keyword(s):  
Activity Coefficient ◽  
Sodium Acetate ◽  
Specific Interaction ◽  
Sodium Perchlorate ◽  
Potassium Bromide ◽  
Association Constants ◽  
Sodium Bromide ◽  
Specific Interactions ◽  
Free Ions

Measurements are reported of the solubility of thallium(I) bromide in aqueous solutions of potassium bromide, sodium perchlorate, barium bromide, and of mixtures of sodium bromide and sodium perchlorate and of sodium bromide and sodium acetate at 25�. The measurements are used to test the merits of two types of ionic activity coefficient expressions, one assuming specific interactions between free ions and the other not. It is shown that neither expression can describe our results adequately, in contrast to previous solubility results with thallium(I) chloride for which the specific interaction expression was adequate.

Activity coefficient assumptions in the determination of association constants. VI. Association of thallium(I) bromide from absorbance measurements

1972 ◽  
Vol 25 (2) ◽  
pp. 311 ◽  
Author(s):  
CY Chan ◽  
MH Panckhurst
Keyword(s):  
Activity Coefficient ◽  
Aqueous Solutions ◽  
Association Constants ◽  
Experimental Results ◽  
Ionic Activity ◽  
Optical Absorbance ◽  
Different Types ◽  
Reasonable Description

Measurements are reported of the optical absorbance of aqueous solutions of thallium(I) bromide in mixture with other electrolytes a t 25°. These measurements are similar to those previously reported1 for thallium(I) chloride and are used in conjunction with two different types of ionic activity coefficient expressions to investigate association of thallium(I) bromide. Both types of expression give a reasonable description of the experimental results but there is the same disagreement with the analysis of solubility measurements found for thallium(1) chloride.

Activity coefficient assumptions in the determination of the association constant of thallium(I) chloride. IV. Spectrophotometric measurements on thallium(I) chloride solutions

1969 ◽  
Vol 22 (2) ◽  
pp. 317 ◽  
Author(s):  
JB Macaskill ◽  
MH Panckhurst
Keyword(s):  
Activity Coefficient ◽  
Aqueous Solutions ◽  
Association Constant ◽  
Association Constants ◽  
Chloride Solutions ◽  
Optical Absorbance ◽  
Different Types

Precise measurements are reported of the optical absorbance of aqueous solutions of thallium(I) chloride in mixture with other electrolytes at 25�. Two types of activity coefficient expressions are used to analyse the measurements in terms of association of thallium(I) chloride. The method of analysis is similar to that used for solubility measurements1-3 and the different types of measurements lead to different values for the association constants.

scholarly journals Determination of Selected Pesticide Residues in River Water Using SBSE Technique

2017 ◽  
Vol 65 (5) ◽  
pp. 1595-1599 ◽  
Author(s):  
Andrea Purdešová
Keyword(s):  
Sodium Chloride ◽  
Ionic Strength ◽  
Pesticide Residues ◽  
Analytical Procedure ◽  
Stir Bar Sorptive Extraction ◽  
Organic Modifier ◽  
Sorptive Extraction ◽  
Fast Gc ◽  
Optimized Conditions

The analytical procedure based on stir‑bar sorptive extraction technique, for the determination of selected pesticide residues (diazinon, malathion, cyprodinyl, penconazole, fludioxonyl, pyriproxyfen, boscalid, pyraclostrobin) is described. Analysis was performed using the commercial TwisterTM stir bar for sorptive extraction. It consists of a 2.0‑cm‑long glass‑encapsulated magnetic stir bar externally coated with PDMS. The extracts were off‑line analyzed using fast GC‑MS in SIM mode. Optimized conditions were established as follows concerning extraction time, stirring speed, aqueous medium characteristics (ionic strength and polarity) respectively: 120 min (700 rpm), addition of 4 g of sodium chloride, no addition of methanol as organic modifier, and 30 min ultrasonic desorption in acetonitrile. Recoveries ranged from 38 % to 58 % (RSD < 15 %, n = 6). Validated limits of quantification in matrix were between 1.6 ngL−1 and 548.8 ngL−1, depending on the compound.

Specific ionic interactions and solubility activity product of caesium perrhenate at 298.10 K

1978 ◽  
Vol 31 (7) ◽  
pp. 1411 ◽  
Author(s):  
C Chan ◽  
KH Khoo ◽  
MH Panckhurst
Keyword(s):  
Activity Coefficient ◽  
Aqueous Solutions ◽  
Specific Interaction ◽  
The Other ◽  
Interaction Parameters ◽  
Ionic Interactions ◽  
Aqueous Mixtures ◽  
Ionic Interaction ◽  
Ionic Activity ◽  
Activity Product

The solubilities of caesium perrhenate in aqueous CsCl, NaCl, KCl and KReO4 solutions at 298.10 K are reported. The solubility activity product for CsReO4 was determined by using extrapolation functions involving two different mean ionic activity coefficient expressions and the results were compared; the total ionic strengths of all the saturated perrhenate solutions were less than 0.1 mol dm-3. One of these expressions used is that proposed recently by Panckhurst and Macaskill1,2 which is an extension of Guggenheim's approach,3,4 specific ionic interactions in aqueous solutions being explicitly taken into account. Its use led to more consistent values for the solubility activity product for CsReO4 than those obtained with the other expression which does not incorporate specific interaction parameters. Values of specific ionic interaction parameters for caesium, potassium and sodium perrhenates in dilute aqueous mixtures with CsCl, KCl, KReO4, KI or NaCl are also reported.

Activity coefficient assumptions in the determination of association constants. VII. Explicit assumptions in the analysis of solubility and absorbance measurements on thallium(I) chloride and bromide

1972 ◽  
Vol 25 (2) ◽  
pp. 317 ◽  
Author(s):  
CY Chan ◽  
MH Panckhurst
Keyword(s):  
Activity Coefficient ◽  
Interaction Coefficient ◽  
Association Constants ◽  
Halide Ions ◽  
Ionic Interaction ◽  
Interaction Coefficients ◽  
Ionic Activity ◽  
Common Ion ◽  
Absorbance Data

In an attempt to resolve discrepancies between association constants obtained from solubility and absorbance measurements for thallium(1) chloride and bromide the explicit assumptions used in the various analyses have been considered in detail. It is shown that the discrepancies can be accounted for in part by considering the activity coefficient of the complex TlCl or TIBr, and, more importantly, by allowing for the presence of small amounts of higher complexes in analysing absorbance data. It is also shown, in determining association constants using a specific ionic activity coefficient expression, that uncertainties in some interaction coefficients reduce the usefulness of our solubility measurements in non-common ion salts. In particular, it is concluded, using the specific ionic interaction coefficient expression, that association constants can at present only be arrived at from solubility measurements by specifying arbitrary interaction coefficients for thallium(1) and halide ions; and to obtain association constants using a non-specific ionic activity coefficient expression it is necessary to assume unnecessarily arbitrary subsidiary association reactions as well as an arbitrary value for the activity coefficient parameter B.

Sodium activity, sodium concentration, and osmolality in plasma in acute and chronic renal failure.

1985 ◽  
Vol 31 (11) ◽  
pp. 1811-1814 ◽  
Author(s):  
E Langhoff ◽  
J Ladefoged
Keyword(s):  
Renal Failure ◽  
Chronic Renal Failure ◽  
Sodium Chloride ◽  
Activity Coefficient ◽  
Plasma Osmolality ◽  
Sodium Concentration ◽  
Ionic Activity ◽  
Sodium Activity ◽  
Before And After ◽  
Healthy Persons

Abstract We compared the ionic activity of sodium, as measured with glass electrodes, with sodium concentration in 23 healthy persons, 15 persons with acute renal failure, and before and after dialysis in 46 patients with chronic renal failure. In healthy persons the mean (+/- SEM) sodium concentration was 139.1 +/- 0.6 mmol/L, whereas the ionic activity was equal to that of a 145.2 +/- 0.5 mmol/L solution of sodium chloride. Variation in the concentration of plasma protein was the most important factor influencing the sodium activity coefficient (the ratio between activity and concentration). The sodium activity coefficient in plasma water (corrected for the non-aqueous phase of the plasma) was fairly constant, being 96% of that in a 140 mmol/L solution of sodium chloride. Thus sodium binds to non-protein molecules and sodium ions interact with other substances in uremic plasma only to a very limited extent. The sum of the molar activities of sodium, potassium, urea, and creatinine was closely and linearly correlated with plasma osmolality, both before and after dialysis.

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