Densities and excess molar volumes of formic acid, acetic acid and propionic acid in pure water and in water + Surf Excel solutions at different temperatures

2005 ◽  
Vol 43 (3) ◽  
pp. 277-288 ◽  
Author(s):  
M. A. Motin ◽  
M. H. Kabir ◽  
E. M. Huque
1991 ◽  
Vol 56 (4) ◽  
pp. 736-744 ◽  
Author(s):  
Ondřej Drábek ◽  
Ivan Cibulka

Excess molar volumes of binary liquid mixtures of (acetic or propionic acid = hexane) at 25 and 35°C, and (acetic or propionic acid + heptane or octane) and (acetic acid + dodecane) at 25°C, measured with a tilting dilution dilatometer, are reported. The excess volumes are positive over the entire concentration range for all mixtures and increase with increasing length of an alkane molecule, decrease with increasing of the alkyl chain in a molecule of carboxylic acid, and increase with increasing temperature.


1965 ◽  
Vol 43 (8) ◽  
pp. 2254-2258 ◽  
Author(s):  
C. C. Lee ◽  
Edward W. C. Wong

endo-Norbornyl-2-d p-bromobenzenesulfonate was synthesized and the isotope effects, as measured by kH/kD, were determined over a range of temperatures for solvolyses in 30% water – 70% dioxane, acetic acid, and formic acid. Values of kH/kD are of the order of 1.20. The data appear to indicate slightly higher isotope effects as the solvents are changed from aqueous dioxane to acetic acid to formic acid, as well as somewhat higher isotope effects at lower temperatures. Possible mechanistic implications of these results are presented. Relative titrimetric acetolysis rates, kexo/kendo, at different temperatures, and enthalpies and entropies of activation for these acetolyses are evaluated and discussed.


2010 ◽  
Vol 10 (2) ◽  
pp. 3937-3974 ◽  
Author(s):  
S. R. Tong ◽  
L. Y. Wu ◽  
M. F. Ge ◽  
W. G. Wang ◽  
Z. F. Pu

Abstract. A study of the atmospheric heterogeneous reactions of formic acid, acetic acid, and propionic acid on dust particles (α-Al2O3) was performed at ambient condition by using a diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) reactor. From the analysis of the spectral features, observations of carboxylates formation provide strong evidence for an efficient reactive uptake process. Comparison of the calculated and experimental vibrational frequencies of adsorbed carboxylates establishes the bridging coordinated structures on the surface. The uptake coefficients of formic acid, acetic acid, and propionic acid on α-Al2O3 particles are (2.07±0.26)×10−3, (5.00±0.69)×10−3, and (3.04±0.63)×10−3, respectively (using geometric area). Besides, the effect of various relative humid (RH) on this heterogeneous reactions was studied. The uptake coefficients of monocarboxylic acids on α-Al2O3 particles increase initially (RH<20%) and then decrease with the increased RH (RH>20%) which was due to the effect of water on carboxylic acids solvation, particles surface hydroxylation, and competition on reactive site. On the basis of the results of experimental simulation, the mechanism of heterogeneous reaction of dust with carboxylic acids at ambient condition was discussed. The loss of atmospheric monocarboxylic acids due to reactive uptake on available mineral dust particles can be competitive with homogeneous loss pathways, especially in dusty urban and desertified environments.


2015 ◽  
Vol 55 (3) ◽  
pp. 294-300 ◽  
Author(s):  
Tarek Abd El-Ghafar El-Shahawy

AbstractLife cannot exist without water. Appropriate management of water, from the water’s source to its utilization, is necessary to sustain life. Aquatic weeds pose a serious threat to aquatic environments and related eco-environments. Short- and long-term planning to control aquatic weeds is extremely important. Water hyacinth,Eichhornia crassipes(Mart.) Solms, is one of the world’s worst pests with a bad reputation as an invasive weed. In this study we are seeking the possibility of using certain chemicals with a natural background, for controlling water hyacinth since there is a delicate balance that needs to be taken into account when using herbicides in water. Five compounds, namely: acetic acid, citric acid, formic acid, and propionic acid, in three concentrations (10, 15, and 20%) were applied (i.e. as a foliar application under wire-house conditions) and compared with the use of the herbicide glyphosate (1.8 kg ∙ ha−1). All of the five compounds performed well in the control of the water hyacinth. As expected, the efficacy increased as the concentration was increased from 10 to 20%. With formic and propionic acids, the plants died earlier than when the other acids or the herbicide glyphosate, were used. Acetic acid came after formic and propionic acids in terms of efficacy. Citric acid ranked last. Formic acid/propionic acid mixtures showed superior activity in suppressing water hyacinth growth especially at the rate of (8 : 2) at the different examined concentrations (3 or 5 or 10%) compared to the formic acid/acetic acid mixtures. Using the formic acid/propionic acid mixture (8 : 2; at 3%) in the open field, provided good control and confirmed the viability of these chemicals in the effective control of water hyacinth. Eventually, these chemical treatments could be used on water for controlling water hyacinth. In the future, these chemicals could probably replace the traditional herbicides widely used in this regard. These chemicals are perceived as environmentally benign for their rapid degradation to carbon dioxide and water. For maximum efficiency thorough coverage especially in bright sunlight is essential.


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