The Spectrophotometry of Sodium Nitrite Solutions in Aqueous Sulphuric and Perchloric Acids and the Equilibrium between Nitrosonium Ion and Nitrous Acid

1963 ◽  
Vol 16 (6) ◽  
pp. 933 ◽  
Author(s):  
NS Bayliss ◽  
R Dingle ◽  
DW Watts ◽  
RJ Wilkie
Keyword(s):  
Aqueous Solutions ◽  
Sulphuric Acid ◽  
Sodium Nitrite ◽  
Perchloric Acid ◽  
Nitrous Acid ◽  
Experimental Error ◽  
Equilibrium Constants ◽  
Solvent Systems ◽  
Nitrosonium Ion

The spectra of solutions of sodium nitrite in aqueous solutions of sulphuric and perchloric acids have been measured at a number of temperatures, and from these spectra the concentrations of the species HNO2 and NO+ have been calculated over the acid-concentration ranges 0-100% sulphuric acid (by wt.) and 0-72% perchloric acid (by wt.). The changes due to temperature were found to be less than the experimental error in the determination of the concentrations of nitrous acid and nitrosonium ion. The equilibria of importance in such systems are discussed and equilibrium constants have been calculated for the reactions H2SO4 + HNO2 <=> H2O + NO+ + HSO4- and HClO4 + HNO2 H2O + NO+ + ClO4- Attempts have been made to correlate the determined values for the concentration of nitrous acid and nitrosonium ion with the acidity functions J0, C0, and Hr for both solvent systems. The nitroacidium ion (H2NO2+) in these systems is found to be less important than previously thought.'

scholarly journals Rhodamine-Sulphuric Acid -A New Visualization Reagent for the Determination of Sucralose by HPTLC

2010 ◽  
Vol 7 (s1) ◽  
pp. S559-S565 ◽  
Author(s):  
Mohd Idris ◽  
Seema Srivastava ◽  
T. R. Baggi ◽  
S. K. Shulka ◽  
A. K. Ganjoo
Keyword(s):  
Sulphuric Acid ◽  
Limit Of Detection ◽  
Solvent System ◽  
Artificial Sweetener ◽  
Yellow Fluorescence ◽  
Relative Standard ◽  
Golden Yellow ◽  
Solvent Systems ◽  
Olive Green

Sucralose a UV-visible inactive compound was separated on silica gel plate without any plate treatment prior to analysis, derivatized with rhodamine - sulphuric acid reagent and detected densitometrically at 456 nm as olive green band. With this reagent sucralose also shows golden yellow fluorescence at 366 nm. Two new solvent systemsi.e. chloroform: methanol: toluene (v/v 5:3.5:1.5) (solvent system-I) and chloroform: ethanol: benzene (v/v 5:3:2) (solvent system-II) were developed and giving Rfvalues of 0.62 and 0.45 respectively. The method was found to be sensitive with good limit of detection (LOD) for two solvent systems. The method imparts specificity to the method as at 456 nm sucralose only gives olive green color spots where as other artificial sweeteners did not show any response to this reagent, where as carbohydrates gives black color spots. Similarly sucralose gives golden yellow fluorescence at 366 nm which is not given by any other artificial sweetener. The method was highly reproducible with relative standard deviation (RSD)≤3% (n=3) and was applied for the determination of sucralose in different matrices like cola drinks, lemon juices, sugar free sweets, tabletop sweeteners etc.etc.

THE DETERMINATION OF SMALL AMOUNTS OF FLUORINE IN WATER

1940 ◽  
Vol 18b (6) ◽  
pp. 151-159 ◽  
Author(s):  
Osman James Walker ◽  
Gordon Roy Finlay
Keyword(s):  
Sulphuric Acid ◽  
Perchloric Acid ◽  
Colorimetric Method ◽  
Fluorine Content ◽  
Sodium Ions ◽  
Ferric Ions ◽  
Titration Method

In the survey of Alberta waters in which fluorine content is compared with the prevalence of mottled teeth, the titration method and the colorimetric method for determining fluorine have not always given comparable results. Good results with the titration method are obtained when distillation is carried out with perchloric acid instead of with sulphuric acid. It was found that the colorimetric method is affected by more than 2 p.p.m. of phosphate, aluminium, or ferric ions, and by over 120 p.p.m. of sulphate ions. Moderate amounts of manganous, ferrous, silicate, chloride, and sodium ions do not interfere. When the water contains over 2 p.p.m. of phosphate, aluminium, or ferric ions, or if the water is coloured, the titration method is used. A scheme for correcting for sulphate ions is proposed. The titration method and the colorimetric method used in this laboratory for determining fluorine in waters are given in detail.

scholarly journals DETERMINATION OF TYPE OF SOLVATE OF PHOSPHORIC ACID DURING ITS EXTRACTION BY TRIBUTYL PHOSPHATE

2019 ◽  
Vol 62 (5) ◽  
pp. 104-109
Author(s):  
Nikolai F. Kizim ◽  
Anastasiya E. Tarasenkova
Keyword(s):  
Phosphoric Acid ◽  
Aqueous Solutions ◽  
Aqueous Phase ◽  
Equilibrium Constants ◽  
Material Balance ◽  
Mass Action ◽  
Acid Extraction ◽  
Processes And Reactions ◽  
Ionic Equilibria

The extraction of phosphoric acid with a solution of tri-n-butyl phosphate (TBP) in toluene from its individual aqueous solutions in a concentration range of 0-11 M is investigated. The experiments are performed at room temperature (20 ± 1 °С). The isotherms of extraction of phosphoric acid under conditions of equality of the volumes of the saturating aqueous phase and the receiving organic phase are constructed. The extraction isotherm is nonlinear, but to an acid concentration in the aqueous phase of ~ 8 M, it is close to linear, and at higher concentrations, the amount of extracted acid increases harshly. To establish the mechanism of acid extraction in the system phosphoric acid – 0.1 M solution of TBP in toluene the method of combining a laboratory and computational experiment is proposed. The optimal parameters describing the extraction of phosphoric acid from natural aqueous solutions are determined. Calculations performed in two approximations were made. In the first approximation the condition of ideality of systems is accepted. In the second approximation the deviations of the properties of phosphoric acid solutions in aqueous solution are taken into account. For the two approximations the preferential extraction of phosphoric acid molecules in the form of H3PO4 ∙ nTBP type solvates (where n = 1, 3) is shown. In the range of concentrations of phosphoric acid in the aqueous phase from 6 to 11 M, the values of equilibrium constants are estimated, which describe the processes and reactions occurring in the system: stepwise dissociation of acid, distribution of TBP, formation of solvates of phosphoric acid, distribution of the resulting solvates of acid, displacement of ionic equilibria in aqueous phase. Mathematically these processes are taken into account using the law of mass action and the equations of material balance. It is believed that the system has established an equilibrium corresponding to a given temperature and pressure. The calculated values of solvate concentrations are in satisfactory agreement with experimental data.

Cefoxitin interferes with the "Clini-Skreen" column method for urinary 17-hydroxycorticosteroids.

1987 ◽  
Vol 33 (7) ◽  
pp. 1219-1222
Author(s):  
M H Kroll ◽  
A J Jackson ◽  
R J Elin
Keyword(s):  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Rate Constants ◽  
Equilibrium Constants ◽  
Molar Absorptivity ◽  
The Other ◽  
Absorbance Maximum ◽  
Column Method ◽  
Apparent Concentration

Abstract Cefoxitin interferes with determination of urinary 17-hydroxycorticosteroids. The apparent concentration of hormone is increased from three- to 10-fold in samples from patients receiving cefoxitin when the Amberlite XAD-2 "Clini-Skreen" column is used. To determine the mechanism of interference, we reacted aqueous solutions of cefoxitin, cortisol, cortisone, and 11-deoxycortisol with phenylhydrazine; recorded the adsorption spectra; and determined the molar absorptivities and the equilibrium and rate constants. Also, we recorded the absorption spectra of phenylhydrazine with eight other cepha antibiotics and benzylpenicillin. Cortisol, cortisone, 11-deoxycortisol, and cefoxitin react with phenylhydrazine and absorb light with superimposable spectra and absorption maxima of 410 nm. The other antibiotics react with phenylhydrazine but absorbance maxima of the products vary, none being at 410 nm. Cortisol, cortisone, and 11-deoxycortisol react with phenylhydrazine 35-fold faster, have equilibrium constants ninefold greater, and have molar absorptivities 1.6 times that of cefoxitin. Thus, cefoxitin interferes with determination of urinary 17-hydroxycorticosteroids by forming a chromophore with the same absorbance maximum and with a molar absorptivity similar to cortisol, but much more slowly.

Nonaqueous Titration of Halides of Nitrogenous Bases, Using Trifluoromethyl Sulfonic Acid

1986 ◽  
Vol 69 (4) ◽  
pp. 620-624 ◽  
Author(s):  
N Aziz Zakhari ◽  
K Artur Kovar
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Perchloric Acid ◽  
Sulfonic Acid ◽  
Glacial Acetic Acid ◽  
Visual Detection ◽  
Phenothiazine Derivatives ◽  
Solvent Systems ◽  
Anhydrous Acetic Acid

Abstract Trifluoromethyl sulfonic acid in glacial acetic acid has been compared with perchloric acid as a titrant in 4 solvent systems: glacial acetic acid, acetic anhydride, a mixture of both, and acetone. The comparison was limited to the determination of halides of nitrogenous bases with and without the use of mercury(II) acetate reagent. The results of the visual titrations showed that both acids are comparable tit rants. However, trifluoromethyl sulfonic acid proved to be superior to perchloric acid in potentiometric titrations carried out in acetic acid-acetic anhydride mixtures. Moreover, the nonoxidizing properties exhibited by trifluoromethyl sulfonic acid proved advantageous over perchloric acid in the visual detection of end points in the titration of phenothiazine derivatives in anhydrous acetic acid, using crystal violet indicator.

Determination of Ionic Mobilities of Uranium in Aqueous Solutions at 25 °C by Use of Conductivities

1977 ◽  
Vol 32 (2) ◽  
pp. 186 ◽  
Author(s):  
G. Marx ◽  
W.-D. Wittke
Keyword(s):  
Aqueous Solutions ◽  
Perchloric Acid ◽  
Pure Water ◽  
Ionic Conductance ◽  
Conductivity Measurements ◽  
Ionic Mobilities

In pure water the limiting ionic conductance of (½ UO22+) was found to be 57 cm2 Ω-1 mol-1 by use of conductivity measurements of UO2 (ClO4)2 • xH2O in diluted perchloric acid

Determination of the activity coefficients in the aliphatic alcohol-non-polar solvent systems

1987 ◽  
Vol 52 (9) ◽  
pp. 2142-2148 ◽  
Author(s):  
Jaromír Hejda ◽  
Věra Jedináková
Keyword(s):  
Aqueous Solutions ◽  
Boric Acid ◽  
Activity Coefficients ◽  
Organic Phase ◽  
Aliphatic Alcohol ◽  
Polar Solvent ◽  
Acid Extraction ◽  
Solvent Systems ◽  
Main Component

A method is proposed for the determination of the activity coefficients in aliphatic alcohols-non-polar solvent systems that are the main component of the organic phase in the boric acid extraction from aqueous solutions.

The extraction of sulphuric acid with Di- and Tri-(3,5,5-trimethylhexyl)amines

1967 ◽  
Vol 20 (11) ◽  
pp. 2375 ◽  
Author(s):  
RW Cattrall
Keyword(s):  
Aqueous Solutions ◽  
Sulphuric Acid ◽  
Equilibrium Constants ◽  
Isoamyl Alcohol ◽  
Aggregation Phenomenon ◽  
Amine Salts

Equilibrium constants have been obtained for the distribution of sulphuric acid between aqueous solutions and isoamyl alcohol solutions of di- and tri-(3,5,5-trimethylhexyl)amines forming the normal amine sulphates and the amine bisulphates. The extraction follows a simple equilibrium law using a solvent for the amines (isoamyl alcohol) in which it has also been shown that no aggregation phenomenon of the amine salts occurs.

The spectra and equilibria of nitrosonium ion, nitroacidium ion, and nitrous acid in solutions of sulphuric, hydrochloric, and phosporic acids

1956 ◽  
Vol 9 (3) ◽  
pp. 319 ◽  
Author(s):  
NS Bayliss ◽  
DW Watts
Keyword(s):  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Nitrous Acid ◽  
Ultraviolet Spectrum ◽  
Total Conversion ◽  
Activity Data ◽  
Chloride Activity ◽  
Nitrosonium Ion ◽  
High Chloride ◽  
Important Constituent

The ultraviolet spectrum of sodium nitrite in aqueous sulphuric acid is essentially that of nitrous acid below 40 per cent, acid, and that of nitrosonium ion above 70 per cant. acid. In the intermediate range there is evidence that the nitroacidium ion (H2NO2+) is an important constituent of the solution. Equilibria involving the three species have been calculated using activity data for water and sulphuric acid. Similar results are obtained in aqueous phosphoric acid as a solvent. In hydrochloric acid of low water activity the high chloride activity causes what appears to be almost total conversion to nitrosyl chloride. The ultraviolet spectrum of the nitrosonium ion is a structureless transition with εmax.=3850 at about 46 kK (2200 Ǻ). The nitroacidium ion does not absorb appreciably within the accessible range.

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