Mixture of two or more liquids whose proportions do not change when the mixture is distilled
Not to be confused with Allotrope.
Vapour-liquid equilibrium of 2-propanol/water showing positive azeotropic behaviour
An azeotrope (/əˈziːəˌtroʊp/)[1] or a constant heating point mixture is a mixture of two or more components in fluidic states whose proportions cannot be altered or changed by simple distillation.[2] This happens because when an azeotrope is boiled, the vapour has the same proportions of constituents as the unboiled mixture. Azeotropic mixture behavior is important for fluid separation processes.
Each azeotrope has a characteristic boiling point. The boiling point of an azeotrope is either less than the boiling point temperatures of any of its constituents (a positive azeotrope), or greater than the boiling point of any of its constituents (a negative azeotrope). For both positive and negative azeotropes, it is not possible to separate the components by fractional distillation and azeotropic distillation is usually used instead.
For technical applications, the pressure-temperature-composition behavior of a mixture is the most important, but other important thermophysical properties are also strongly influenced by azeotropy, including the surface tension[3][4][5] and transport properties.[6][7]
Some azeotropic mixtures of pairs of compounds are known,[8] and many azeotropes of three or more compounds are also known.[9]
^"Azeotrope definition and meaning - Collins English Dictionary". www.collinsdictionary.com.
^Moore, Walter J. Physical Chemistry, 3rd e Prentice-Hall 1962, pp. 140–142
^Staubach, Jens; Stephan, Simon (28 September 2022). "Interfacial properties of binary azeotropic mixtures of simple fluids: Molecular dynamics simulation and density gradient theory". The Journal of Chemical Physics. 157 (12): 124702. doi:10.1063/5.0100728. ISSN 0021-9606.
^McLure, I. A.; Edmonds, B.; Lal, M. (1973). "Extremes in Surface Tension of Fluorocarbon + Hydrocarbon Mixtures". Nature Physical Science. 241 (107): 71–71. doi:10.1038/physci241071a0. ISSN 0300-8746.
^Schäfer, Elisabeth; Sadowski, Gabriele; Enders, Sabine (January 2014). "Interfacial tension of binary mixtures exhibiting azeotropic behavior: Measurement and modeling with PCP-SAFT combined with Density Gradient Theory". Fluid Phase Equilibria. 362: 151–162. doi:10.1016/j.fluid.2013.09.042. ISSN 0378-3812.
^"95/05209 Transport properties of ternary near-azeotropic mixtures". Fuel and Energy Abstracts. 36 (5): 365. September 2009. doi:10.1016/0140-6701(95)96948-c. ISSN 0140-6701. Retrieved 24 March 2007.
^Fertig, David; Hasse, Hans; Stephan, Simon (December 2002). "Transport properties of binary Lennard-Jones mixtures: Insights from entropy scaling and conformal solution theory". Journal of Molecular Liquids. 367: 120401. doi:10.1016/j.molliq.2022.120401. ISSN 0167-7322.
^Cite error: The named reference hilmen was invoked but never defined (see the help page).
^Department of Chemical Engineering University of Alicante. "Numerical Determination of Distillation Boundaries for Multicomponent Homogeneous and Heterogeneous Azeotropic Systems" (PDF). Archived from the original (PDF) on 1 October 2011.
An azeotrope (/əˈziːəˌtroʊp/) or a constant heating point mixture is a mixture of two or more components in fluidic states whose proportions cannot be...
of azeotrope data for various binary and ternary mixtures of solvents. The data include the composition of a mixture by weight (in binary azeotropes, when...
easily form azeotropes. Commonly, these azeotropes are referred to as a low boiling azeotrope because the boiling point of the azeotrope is lower than...
allows a new ternary azeotrope comprising the ethanol, water, and the entraining agent to be formed. This lower-boiling ternary azeotrope is removed preferentially...
azeotropic distillation is any of a range of techniques used to break an azeotrope in distillation. In chemical engineering, azeotropic distillation usually...
adding sodium chloride in a process known as salting out. It forms an azeotrope with water, resulting in a boiling point of 80.37 °C and is characterized...
binary (two-component) mixture of HCl and H2O has a constant-boiling azeotrope at 20.2% HCl and 108.6 °C (381.8 K; 227.5 °F). There are four constant-crystallization...
in the pure liquid. An example is the azeotrope of approximately 95% ethanol and water. Because the azeotrope's vapor pressure is higher than predicted...
production is still in use today. Commercially available nitric acid is an azeotrope with water at a concentration of 68% HNO3. This solution has a boiling...
liquid Odor acrid Density 1.70 g/mL, azeotrope (57% HI by weight) Boiling point 127 °C (261 °F; 400 K) 1.03 bar, azeotrope Solubility in water Aqueous solution...
the KHSO4 and by distilling off the water until the solution reaches an azeotrope (124.3 °C). The yield is approximately 85%. Hydrobromic acid is available...
of SCl2 from S2Cl2 is possible via distillation with PCl3 to form an azeotrope of 99% purity, however sulfur dichloride loses chlorine slowly at room...
A heteroazeotrope is an azeotrope where the vapour phase coexists with two liquid phases. Sketch of a T-x/y equilibrium curve of a typical heteroazeotropic...
high-boiling, relatively non-volatile component, the solvent, that forms no azeotrope with the other components in the mixture. The method is used for mixtures...
centers. An example is hydronium perchlorate. Perchloric acid forms an azeotrope with water, consisting of about 72.5% perchloric acid. This form of the...
Aqueous solutions that are 47.6% HBr by mass form a constant-boiling azeotrope mixture that boils at 124.3 °C (255.7 °F). Boiling less concentrated solutions...
significant vapor pressure at the steam's temperature. If the water forms an azeotrope with the substances of interest, the boiling point of the mixture may...
processes, as a mixture of ethanol and water becomes a minimum-boiling azeotrope at this concentration. However, rectified spirit is typically distilled...
tasted in water at 0.53 to 1.8 ppm. Xylenes form azeotropes with water and a variety of alcohols. The azeotrope with water consists of 60% xylenes and boils...
reactive and non-reactive zones, the heterogeneous azeotrope or a composition close to the azeotrope can be obtained as the distillate product. Moreover...
ethanol production) from ethanol process streams due to the formation of an azeotrope at around 95.6 percent concentration by weight, molecular sieve beads...
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