Semi-empirical calculations on the structure of the oxonium ion in various crystal sites and relative acidity scale

1976 ◽  
Vol 42 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Michel Fournier ◽  
Marcel Allavena ◽  
Antoine Potier
Keyword(s):  
Semi Empirical ◽  
Acidity Scale ◽  
Relative Acidity

scholarly journals THE RELATIVE ACID STRENGTHS OF SUBSTITUTED PICRIC ACIDS

1964 ◽  
Vol 42 (5) ◽  
pp. 1106-1109 ◽  
Author(s):  
John W. Elder ◽  
Raymond P. Mariella
Keyword(s):  
Acetic Acid ◽  
Inorganic Acids ◽  
Aqueous Method ◽  
Aqueous Conditions ◽  
Acidity Scale ◽  
Relative Acidity

The relative acidity of substituted picric acids has been determined using special non-aqueous titration techniques. Other organic and inorganic acids, whose acidities in water are well known, were also determined using this non-aqueous method. A correlation of the relative acidities of known acids in water with the relative acidities of these same acids, as measured under the non-aqueous conditions used, was excellent. Using this technique a single relative acidity scale was determined ranging from acids as strong as perchloric to acids as weak as acetic acid.

scholarly journals Iono-Covalent Character of the Metal–Oxygen Bonds in Oxides: A Comparison of Experimental and Theoretical Data

2004 ◽  
Vol 27 (1) ◽  
pp. 1-60 ◽  
Author(s):  
M. Lenglet
Keyword(s):  
Chemical Bond ◽  
Mixed Oxides ◽  
Hybrid Methods ◽  
Theoretical Data ◽  
Covalent Character ◽  
Standard Methods ◽  
Binary Oxides ◽  
B3lyp Method ◽  
Semi Empirical ◽  
Acidity Scale

The aim of this paper is to review the actual data on the chemical bond in binary and mixed oxides. The electronegativity(χM)and the aciditypascales are the most significant semi-empirical concepts for predicting the trend of bonding character in iono-covalent oxides. A satisfactory correlation between the data issued from the acidity scale and the calculated ionic charges has been established.The most recent studies show that the hybrid methods such as the B3LYP method lead to more reliable results for the description of structural, energetic and electronic properties of binary oxides than those from standard methods.

Relative acidity scale of bile acids through ESI-MS measurements

2010 ◽  
Vol 8 (16) ◽  
pp. 3674 ◽  
Author(s):  
Olga Bortolini ◽  
Giancarlo Fantin ◽  
Valeria Ferretti ◽  
Marco Fogagnolo ◽  
Pier Paolo Giovannini ◽  
...  
Keyword(s):  
Bile Acids ◽  
Esi Ms ◽  
Acidity Scale ◽  
Relative Acidity

scholarly journals Coulometric-potentiometric determination of autoprotolysis constant and relative acidity scale of water

2010 ◽  
Vol 75 (11) ◽  
pp. 1575-1582 ◽  
Author(s):  
Radmila Dzudovic ◽  
Ljiljana Jaksic
Keyword(s):  
Supporting Electrolyte ◽  
Sodium Perchlorate ◽  
Electrolytic Cell ◽  
Electrode Pair ◽  
Strong Base ◽  
Palladium Electrode ◽  
Oxidation Of Hydrogen ◽  
The Difference ◽  
Acidity Scale ◽  
Relative Acidity

The autoprotolysis constant and relative acidity scale of water were determined by applying the coulometric-potentiometric method and a hydrogen/palladium (H2/Pd) generator anode. In the described procedure for the evaluation of autoprotolysis constant, a strong base generated coulometrically at the platinum cathode in situ in the electrolytic cell, in presence of sodium perchlorate as the supporting electrolyte, is titrated with hydrogen ions obtained by the anodic oxidation of hydrogen dissolved in palladium electrode. The titration was carried out with a glass-SCE electrode pair at 25.0?0.1?C. The value obtained pKw = 13.91 ? 0.06 is in agreement with literature data. The range of acidity scale of water is determined from the difference between the halfneutralization potentials of electrogenerated perchloric acid and that of sodium hydroxide in a sodium perchlorate medium. The halfneutralization potentials were measured using both a glass-SCE and a (H2/Pd)ind-SCE electrode pairs. A wider range of relative acidity scale of water was obtained with the glass-SCE electrode pair.

Relative acidity scale of glycine- and taurine-conjugated bile acids through ESI-MS measurements

Steroids ◽  
2011 ◽  
Vol 76 (6) ◽  
pp. 596-602 ◽  
Author(s):  
Olga Bortolini ◽  
Tatiana Bernardi ◽  
Giancarlo Fantin ◽  
Valeria Ferretti ◽  
Marco Fogagnolo
Keyword(s):  
Bile Acids ◽  
Esi Ms ◽  
Acidity Scale ◽  
Relative Acidity ◽  
Conjugated Bile Acids

scholarly journals Determination of relative acidity scales for some dipolar aprotic solvents by coulometry using a hydrogen-palladium electrode

2008 ◽  
Vol 73 (8-9) ◽  
pp. 871-878 ◽  
Author(s):  
Radmila Dzudovic ◽  
Ljiljana Jaksic
Keyword(s):  
Perchloric Acid ◽  
Supporting Electrolyte ◽  
Sodium Perchlorate ◽  
Electrode Pair ◽  
Tetrabutylammonium Perchlorate ◽  
Palladium Electrode ◽  
The Difference ◽  
Acidity Scale ◽  
Relative Acidity

A coulometric-potentiometric procedure for the determination of relative acidity scales of acetone, methylethyl ketone, methyl-isobutyl ketone and propylene carbonate is described. The range of the relative acidity scale of a solvent was determined from the difference between the half-neutralization potential of perchloric acid and that of tetrabutylammonium hydroxide. The perchloric acid was generated in situ from a hydrogen-palladium electrode in presence of sodium perchlorate or tetrabutylammonium perchlorate as the supporting electrolyte. The electrode pairs glass-SCE and (H2/Pd)ind-SCE were applied for the measurement of the half-neutralization potentials of the acid and base. A wider range of relative acidity scale of the solvents was obtained with the glass-SCE electrode pair and tetrabutylammonium perchlorate as the supporting electrolyte.

scholarly journals The application of hydrogen-palladium electrode for potentiometric acid-base determinations in tetrahydrofuran

2013 ◽  
Vol 78 (8) ◽  
pp. 1203-1212
Author(s):  
Anja Jokic ◽  
Radmila Dzudovic ◽  
Ljiljana Jaksic ◽  
Snezana Nikolic-Mandic
Keyword(s):  
Maleic Acid ◽  
Glass Electrode ◽  
Indicator Electrode ◽  
Electrode Pair ◽  
Acid Base ◽  
Palladium Electrode ◽  
The Individual ◽  
Acidity Scale ◽  
Relative Acidity

The application of the hydrogen-palladium electrode (H2/Pd) as the indicator electrode for the determination of relative acidity scale (Es, mV) of tetrahydrofuran (THF) and the potentiometric titrations of acids in this solvent was investigated. The relative acidity scale tetrahydrofuran was determined from the difference half-neutralization potentials of perchloric acid and tetrabutylammonium hydroxide (TBAH), which were measured by using both H2/Pd-SCE and glass-SCE electrode pairs. The experimentally obtained value of Es scale THF with a H2/Pd-SCE electrode pair was 1155 mV, and those obtained with glass-SCE electrode pair 880 mV. By using a H2/Pd indicator electrode, the individual acids (benzoic acid, palmitic acid, maleic acid, acetyl acetone, ?-naphthol) and two component acid mixtures (benzoic acid + ?-naphthol, palmitic acid + ?-naphthol, maleic acid + ?-naphthol and maleic acid + ftalic acid) were titrated with a standard solution of TBAH. In addition, sodium methylate and potassium hydroxide proved to be very suitable titrating agents for titrating of the individual acids and the acids in mixtures, respectively. The relative error of the determination of acids in mixture was less than 3%. The results are in agreement with those obtained by a conventional glass electrode. The advantages of H2/Pd electrode over a glass electrode in potentiometric acid-base determinations in tetrahydrofuran lie in the following: this electrode gives wider relative acidity scale THF, higher the potential jumps at the titration end-point and relatively fast response time; furthermore, it is very durable, simple to prepare and can be used in the titrations of small volumes.

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