Enthalpies of Mixing for Binary Liquid Mixtures of Acids

1983 ◽  
Vol 38 (12) ◽  
pp. 1400-1401 ◽  
Author(s):  
R. Haase ◽  
H.-J. Jansen ◽  
B. Winter
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Propionic Acid ◽  
Entire Range ◽  
Excess Enthalpy ◽  
Liquid Mixtures ◽  
Binary Liquid ◽  
Calorimetric Measurements ◽  
Liquid Systems ◽  
C 30

Abstract For the binary liquid systems formic acid + acetic acid, formic acid + propionic acid, and acetic acid + propionic acid, we give the results of new calorimetric measurements of the molar excess enthalpy H̄E at 25 °C, 30 °C, 40 °C, and 60°C, covering the entire range of compositions. H̄E is always positive, increases linearly with the temperature, and is slightly asymmetric with respect to the mole fraction x. The composition at the maximum of the function H̄E(x) is independent of the temperature.

Enthalpies of Mixing for Binary Liquid Mixtures of Monocarbonic Acids and Alcohols

1985 ◽  
Vol 40 (9) ◽  
pp. 947-951 ◽  
Author(s):  
R. Haase ◽  
R. Lorenz
Keyword(s):  
Aliphatic Alcohol ◽  
Excess Enthalpy ◽  
Excess Heat Capacity ◽  
Enthalpy Of Mixing ◽  
Liquid Mixtures ◽  
Binary Liquid ◽  
Molar Excess ◽  
Calorimetric Measurements ◽  
Liquid Systems ◽  
Molar Excess Heat Capacity

We present the results of calorimetric measurements of the molar enthalpy of mixing (molar excess enthalpy) H̄E as a function of temperature and composition (described by the mole fraction x of the alcohol) for 18 binary liquid systems consisting of an aliphatic monocarbonic acid (formic, acetic, propionic, butyric, valeric acids) and an aliphatic alcohol (methanol, ethanol, 1-propanol. 2-propanol, 1-butanol, 2-methyl-2-propanol). The experiments cover temperatures between 298.15 K and 318.15 K and the whole range of compositions (usually nearly 40 compositions at each temperature). There is a great variety of behaviour as far as the function H̄E(x) for T= const is concerned. Many systems show endothermic mixing ( H̄E > 0), other systems exothermic mixing (H̄E < 0), again other systems partly endothermic, partly exothermic behaviour. There is one case (acetic acid + 2-methyl-2-propanol) where H̄E(x) changes its sign twice and the molar excess heat capacity exhibits unusually large negative values.

Enthalpies of Mixing for the Liquid System Formic Acid + Acetic Acid

1979 ◽  
Vol 34 (5) ◽  
pp. 659-660
Author(s):  
R. Haase ◽  
H.-J. Jansen ◽  
K. Puder ◽  
B. Winter
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Mole Fraction ◽  
Excess Enthalpy ◽  
Liquid System ◽  
Short Description ◽  
Enthalpies Of Mixing ◽  
Calorimetric Measurements ◽  
C 30 ◽  
Increasing Temperature

Abstract After a short description of the evaluation of the calorimetric measurements, we give the results for the enthalpies of mixing in the liquid system formic acid + acetic acid. The molar excess enthalpy H̄E has been determined as a function of the mole fraction x of acetic acid at 18 °C, 20 °C, 25 °C, 30 °C, and 40 °C. The function H̄E (x) is always positive and nearly symmetric (with a maximum at about x = 0.5) and increases with increasing temperature. A three-parameter fit of the function H̄E (x) has been achieved for each temperature.

Excess molar volumes of binary mixtures of acetic acid and propionic acid with some members of homologous series of alkanes

1991 ◽  
Vol 56 (4) ◽  
pp. 736-744 ◽  
Author(s):  
Ondřej Drábek ◽  
Ivan Cibulka
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Alkyl Chain ◽  
Excess Molar Volumes ◽  
Liquid Mixtures ◽  
Entire Concentration Range ◽  
Molar Volumes ◽  
Binary Liquid ◽  
Alkane Molecule ◽  
Increasing Temperature

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.

scholarly journals Heterogeneous chemistry of monocarboxylic acids on α-Al<sub>2</sub>O<sub>3</sub> at ambient condition

2010 ◽  
Vol 10 (2) ◽  
pp. 3937-3974 ◽  
Author(s):  
S. R. Tong ◽  
L. Y. Wu ◽  
M. F. Ge ◽  
W. G. Wang ◽  
Z. F. Pu
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Carboxylic Acids ◽  
Propionic Acid ◽  
Ambient Condition ◽  
Heterogeneous Reactions ◽  
Dust Particles ◽  
Monocarboxylic Acids ◽  
Al2o3 Particles ◽  
Α Al2o3

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.

Excess molar volumes and viscosities of binary mixtures of some polyethers with propylamine at 298.15 K

2002 ◽  
Vol 80 (5) ◽  
pp. 467-475 ◽  
Author(s):  
Amalendu Pal ◽  
Rakesh Kumar Bhardwaj
Keyword(s):  
Experimental Data ◽  
Viscous Flow ◽  
Binary Mixtures ◽  
Entire Range ◽  
Excess Volume ◽  
Excess Molar Volumes ◽  
Liquid Mixtures ◽  
Molar Volumes ◽  
Binary Liquid ◽  
Volume Viscosity

Excess molar volumes (VmE) and dynamic viscosities (η) have been measured as a function of composition for binary liquid mixtures of propylamine with 2,5-dioxahexane, 2,5,8-trioxanonane, 2,5,8,11-tetraoxadodecane, 3,6,9-trioxaundecane, and 5,8,11-trioxapentadecane at 298.15 K. The excess volumes are positive over the entire range of composition for the systems propylamine + 2,5-dioxahexane, and + 3,6,9-trioxaundecane, negative for the systems propylamine + 2,5,8,11-tetraoxadodecane, and + 5,8,11-trioxapentadecane, and change sign from positive to negative for the remaining system propylamine + 2,5,8-trioxanonane. From the experimental data, deviations in the viscosity (Δln η) and excess energies of activation for viscous flow (ΔG*E) have been derived. These values are positive for all mixtures with the exception of propylamine + 2,5-dioxahexane.Key words : excess volume, viscosity, binary mixtures.

scholarly journals Notizen:Mischungsenthalpien beim flüssigen System Wasser + Essigsäure / Heats of Mixing for the Liquid System Water + Acetic Acid

1972 ◽  
Vol 27 (10) ◽  
pp. 1527-1529 ◽  
Author(s):  
R. Haase ◽  
P. Steinmetz ◽  
K.-H. Dücker
Keyword(s):  
Acetic Acid ◽  
Power Series ◽  
Liquid System ◽  
Heat Of Mixing ◽  
Pure Liquid ◽  
Calorimetric Measurements ◽  
Heats Of Mixing ◽  
Free Parameters ◽  
C 30 ◽  
System Water

Calorimetric measurements of the heats of mixing for the liquid system water+acetic acid at 17 °C, 20 °C, 25 °C, 30 °C, 40 °C, and 50 °C show that there is a change of sign in the function H̅E(x), where H̅E denotes the molar heat of mixing and x the mole fraction of acetic acid. The process of mixing the pure liquid components is weakly exothermic for low acid concentrations, but strongly endothermic for high acid concentrations. The function H̅E can be approximately represented by the usual power series with respect to x, five free parameters at each temperature being necessary.

scholarly journals Verdampfungsgleichgewicht und thermodynamisehe Funktionen des flüssigen Systems Wasser + Essigsäure / Vapour-Liquid. Equilibrium and Thermodynamic Functions of the Liquid System Water + Acetic Acid

1973 ◽  
Vol 28 (10) ◽  
pp. 1740-1742 ◽  
Author(s):  
R. Haase ◽  
M. Pehlke ◽  
K.-H. Dücker
Keyword(s):  
Acetic Acid ◽  
Composition Dependence ◽  
Excess Enthalpy ◽  
Excess Entropy ◽  
Liquid System ◽  
Gibbs Function ◽  
Liquid Equilibrium ◽  
Molar Excess ◽  
C 30 ◽  
System Water

Vapour pressures and vapour compositions of the liquid system water + acetic acid have been measured at 25 °C, 30 °C, 35 °C, 40 °C, and 45 °C in the whole range of compositions. The dimerization of acetic acid in the vapour being taken into account, the molar excess Gibbs function ḠE is derived from the measurements. Earlier measurements of the molar excess enthalpy HE are combined with the -GE values to give the molar excess entropy SE. The “symmetry rule” (Haase, 1951) concerning the composition dependence of ḠE, -HE, and S̄E has been confirmed.

scholarly journals Chemicals with a natural reference for controlling water hyacinth, Eichhornia crassipes (Mart.) Solms

2015 ◽  
Vol 55 (3) ◽  
pp. 294-300 ◽  
Author(s):  
Tarek Abd El-Ghafar El-Shahawy
Keyword(s):  
Acetic Acid ◽  
Citric Acid ◽  
Formic Acid ◽  
Propionic Acid ◽  
Water Hyacinth ◽  
Eichhornia Crassipes ◽  
Effective Control ◽  
Acid Mixture ◽  
Aquatic Weeds ◽  
Herbicide Glyphosate

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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