The Activity Coefficients of the Undissociated Part of Weak Acids. I. Acetic Acid in Potassium Acetate Solutions

1939 ◽  
Vol 61 (1) ◽  
pp. 65-67 ◽  
Author(s):  
W. D. Larson ◽  
W. J. Tomsicek

1989 ◽  
Vol 54 (11) ◽  
pp. 2840-2847 ◽  
Author(s):  
Ivona Malijevská ◽  
Alena Maštalková ◽  
Marie Sýsová

Isobaric equilibrium data (P = 101.3 kPa) for the system cyclohexane-acetic acid-propionic acid have been measured by two different analytical techniques. Activity coefficients calculated by simultaneous solving of equations for the chemical and phase equilibria were subjected to a consistency test based on inaccuracies determined from the error propagation law, and were correlated by Wilson’s equation. The activity coefficients measured were compared with those calculated from binary vapour-liquid equilibrium data and with values predicted by the UNIFAC method.



1970 ◽  
Vol 49 (3) ◽  
pp. 621-625 ◽  
Author(s):  
Stephen H.Y. Wei

The electron microprobe was used to analyze the calcium and phosphorus concentrations of sound, acid-etched, and remineralized enamel. By use of a weak acetic acid-potassium acetate buffer, it was found that the demineralization probably affected only the first 10 micrometers of the enamel surface. This demineralized enamel was successfully remineralized by the use of a calcifying solution. The changes in calcium and phosphorus concentrations and the Ca/P ratios were determined.



1991 ◽  
Vol 69 (12) ◽  
pp. 2117-2121 ◽  
Author(s):  
T. S. Banipal ◽  
B. S. Lark ◽  
S. Singh

Total vapour pressures for binary mixtures containing acetic acid, propionic acid, isobutyric acid, and trimethylacetic acid with acetonitrile have been measured for the entire composition range at 298.15 and 318.15 K using a static manometric method. All systems show positive deviations from Raoult's law, enhanced by both an increase in temperature and an increase in the methylation of acetic acid. Activity coefficients have been calculated by taking into consideration the dimerization of these carboxylic acids in the vapour phase. TSE values obtained from GE and earlier reported HE values are found to be negative for acetic acid, about zero for propionic and isobutyric acids, and positive for trimethylacetic acid for the whole composition range. The results have been interpreted in terms of various contributions such as depolymerization, heteromolecular dipole–dipole interactions, and the increasing dimerization constant and steric hindrance with increase of complexity of the acid. Key words: excess Gibbs energy, carboxylic acids, acetonitrile, activity coefficients



1928 ◽  
Vol 50 (3) ◽  
pp. 696-714 ◽  
Author(s):  
Edwin J. Cohn ◽  
Francis F. Heyroth ◽  
Miriam F. Menkin


1953 ◽  
Vol 31 (3) ◽  
pp. 214-215 ◽  
Author(s):  
R. A. Marcus ◽  
C. A. Winkler

An analytical method has been developed for the estimation of nitric acid in acetic acid – acetic anhydride media, with a precision of 0.3%. The procedure involves the addition of a solution of potassium acetate in acetic acid to the sample. The excess is back-titrated conductometrically with a standard solution of nitric acid in acetic acid.



2006 ◽  
Vol 61 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Ilia Manolov ◽  
Caecilia Maichle-Moessmer ◽  
Elke Niquet

AbstractThe base catalyzed condensation reaction between 4-hydroxycoumarin and 3-acetylcoumarin (3-benzoylcoumarin) in water at reflux led to the formation of 1-methyl (1-phenyl)- benzopyrano[4’,3’-c]-benzo[3”,4”-ƒ ]-2,8-dioxabicyclo[3.3.1]nonane (2a, b) as final products. When 4-hydroxycoumarin and 3-acetylcoumarin reacted in a glacial acetic acid in the presence of potassium acetate the final product was 7-[3-acetyl-2-oxo-3,4-dihydro-2H-[1]benzopyran-4-yl]methyl- 6H,14H,14bH-bis-([1]benzopyrano)[4,3-b:4’,3’-d]pyran-6,14-dione (4). 4-Hydroxycoumarin and 4-(5-bromo-2-hydroxyphenyl)-3-buten-2-one were condensed in water at reflux and 1- methylcoumarino-[4’,3’-c]-bromobenzo[3”,4”-ƒ ]-2,8-dioxabicyclo[3.3.1]nonane was a final product (3).



1986 ◽  
Vol 51 (12) ◽  
pp. 2665-2674 ◽  
Author(s):  
Ivona Malijevská ◽  
Helena Perničková ◽  
Karel Ledvinka ◽  
Bohuslav Doležal

Results of measurement of vapour-liquid equilibria in the benzene-propionic acid-acetic acid ternary system at normal pressure are presented. The activity coefficients were, within the framework of inaccuracies determined on the basis of the law of error propagation, subjected to a test of consistency and correlated by the Wilson equation. The experimental values of activity coefficients are compared with the values calculated on the basis of the Wilson equation with its constants obtained both from the ternary and from the binary data and with the values estimated by the UNIFAC method.



Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 502
Author(s):  
Wenyue Kang ◽  
Zhijun Zhang

Glucose and fructose are widely available and renewable resources. They were used to prepare acetic acid (AA) under the catalysis of potassium acetate (KAc) by thermogravimetric analysis (TGA) and pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS). The TGA result showed that the KAc addition lowered the glucose’s thermal decomposition temperatures (about 30 °C for initial decomposition temperature and 40 °C for maximum mass loss rate temperature), implying its promotion of glucose’s decomposition. The Py-GC/MS tests illustrated that the KAc addition significantly altered the composition and distribution of hexose pyrolysis products. The maximum yield of AA was 52.1% for the in situ catalytic pyrolysis of glucose/KAc (1:0.25 wt/wt) mixtures at 350 °C for 30 s. Under the same conditions, the AA yield obtained from fructose was 48% and it increased with the increasing amount of KAc. When the ratio reached to 1:1, the yield was 53.6%. In comparison, a study of in situ and on-line catalytic methods showed that KAc can not only catalyze the primary cracking of glucose, but also catalyze the cracking of a secondary pyrolysis stream. KAc plays roles in both physical heat transfer and chemical catalysis.



RSC Advances ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 1967-1975 ◽  
Author(s):  
Jianhui Wang ◽  
Hongyan Yang ◽  
Gaoxaing Qi ◽  
Xuecheng Liu ◽  
Xu Gao ◽  
...  

The effects of formic acid, acetic acid and levulinic acid on acetone–butanol–ethanol (ABE) fermentation under different pH adjustment conditions were investigated usingClostridium acetobutylicumas the fermentation strain.



1989 ◽  
Vol 43 ◽  
pp. 720-725 ◽  
Author(s):  
George Biedermann ◽  
Anders Molin ◽  
Sine Larsen ◽  
Lene Teuber ◽  
Brigitta Lucanska ◽  
...  


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