Miscible compounds

For water-miscible compounds the use of aqueous solubility data is obviously impossible. 

Percents volatilized in one day for the various media were calculated using initial pesticide amounts and the overall volatilization rate constants, obtained from the half life for volatilization as output by EXAMS. Mevlnphos results are not included here, for as discussed previously, methods for calculation used in EXAMS are not appropriate for water miscible compounds. The experimental and computer predicted percents volatilized in one day are qualitatively similar (Figure 2). Quantitatively, experimental and predicted percents volatilized agreed within a factor of three for diazlnon, methyl parathion, and malathion, and within a factor of five for parathion. Considering the fact that EXAMS was not intended for use with wet soil systems, these results are encouraging. 

MPP extraction (MPPE) technology is applicable to aqueous waste streams contaminated with compounds with a higher affinity for the extraction liquid than for water. Water-miscible compounds such as alcohols and ketones have low affinities for the immobilized extraction... 

A liquid explosive, as the term implies, is an expl substance that is liq at ambient temp. Liquid Explosives (LE) can be pure compounds or mixts of miscible compounds, including aqueous solutions. Expls containing a mixt of liq and solid phases, eg, the so-called Slurry Explosives, as well as Liquid Oxygen Explosives (LOX), are described in separate articles... 

The lesser known four-membered cyclic ether, oxacyclobutane (oxe-tane), (CH2)30, also is cleaved readily, but less so than oxacyclopropane. Oxacyclopentane (oxolane, tetrahydrofuran) is a relatively unreactive water-miscible compound with desirable properties as an organic solvent. It often is used in place of diethyl ether in Grignard reactions and reductions with lithium aluminum hydride. 

These insecticides range from completely water-miscible compounds to essentially insoluble ones, as indicated in Table VI. Most highly water-soluble insecticides are systemic, that is, they are absorbed into the tissues of the growing crop, either through the leaves or through the roots. But some water-miscible compounds are so unstable that their toxicity is destroyed before systemic activity can be observed (12,18). Tepp, for example, has a half life in water of only 8 hours. While many other compounds in this class have only limited solubility in water, they are still effective systemics. Examples are demeton, methyl demeton, and phorate. 

Xanthan gum will dissolve in acids such as 5% acetic acid and remain stable for several months unless the temperature is elevated. Also, xanthan gum is soluble directly in 5% sodium hydroxide solutions. Sodium hydroxide solutions of 0-15% can be thickened, provided the gum is pre-dissolved in water prior to adding the sodium hydroxide solution. These highly alkaline, thickened solutions have exceptional viscosity stability. Water miscible compounds such as ethanol are compatible with xanthan gum solutions up to concentrations of 50%. Solutions, emulsions, and gels that contain xanthan gum have excellent freeze-thaw resistance and many applications in the food industry. 

Suppose a stream containing ethanol and water (two fully miscible compounds) flows into a distillation column at 100 kg/s. Two streams leave the column the vapor stream contains 80% ethanol by mass and the liquid bottoms has an ethanol concentration of 4M. The total liquid stream flowrate is 20 kg/s. Calculate the composition of the entrance stream. 

ILs can be divided in water-immiscible and -miscible compounds. Hydrophobic ILs typically consist of anions such as PF or Tf2N and the hydrophilic ILs of Cl , Br , BF or AICI4. According to Anthony et aL, the water miscibility is affected strongly by the anion [12]. Also the cation has its impact on water affinity, since when the alltyl chain is elongated, miscibility of the ionic liquid is decreased. 

Most properties of linear polymers are controlled by two different factors. The chemical constitution of tire monomers detennines tire interaction strengtli between tire chains, tire interactions of tire polymer witli host molecules or witli interfaces. The monomer stmcture also detennines tire possible local confonnations of tire polymer chain. This relationship between the molecular stmcture and any interaction witli surrounding molecules is similar to tliat found for low-molecular-weight compounds. The second important parameter tliat controls polymer properties is tire molecular weight. Contrary to tire situation for low-molecular-weight compounds, it plays a fimdamental role in polymer behaviour. It detennines tire slow-mode dynamics and tire viscosity of polymers in solutions and in tire melt. These properties are of utmost importance in polymer rheology and condition tlieir processability. The mechanical properties, solubility and miscibility of different polymers also depend on tlieir molecular weights. 

The general case of two compounds forming a continuous series of solid solutions may now be considered. The components are completely miscible in the sohd state and also in the hquid state. Three different types of curves are known. The most important is that in which the freezing points (or melting points) of all mixtures lie between the freezing points (or melting points) of the pure components. The equilibrium diagram is shown in Fig. 7, 76, 1. The hquidus curve portrays the composition of the hquid phase in equihbrium with sohd, the composition of... 

The theory of the process can best be illustrated by considering the operation, frequently carried out in the laboratory, of extracting an orgaiuc compound from its aqueous solution with an immiscible solvent. We are concerned here with the distribution law or partition law which, states that if to a system of two liquid layers, made up of two immiscible or slightly miscible components, is added a quantity of a third substance soluble in both layers, then the substance distributes itself between the two layers so that the ratio of the concentration in one solvent to the concentration in the second solvent remains constant at constant temperature. It is assumed that the molecular state of the substance is the same in both solvents. If and Cg are the concentrations in the layers A and B, then, at constant temperature ... 

If the substance is found to be far too soluble in one solvent and much too insoluble in another solvent to allow of satisfactory recrystallisation, mixed solvents or solvent pairs may frequently be used with excellent results. The two solvents must, of course, be completely miscible. Recrystallisation from mixed solvents is carried out near the boiling point of the solvent. The compound is dissolved in the solvent in which it is very soluble, and the hot solvent, in which the substance is only sparingly soluble, is added cautiously until a slight turbidity is produced. The turbidity is then just cleared by the addition of a small quantity of the first solvent and the mixture is allowed to cool to room temperature crystals will separate. Pairs of liquids which may be used include alcohol and water alcohol and benzene benzene and petroleum ether acetone and petroleum ether glacial acetic acid and water. 

In the isolation of organic compounds from aqueous solutions, use is frequently made of the fact that the solubility of many organic substances in water is considerably decreased by the presence of dissolved inorganic salts (sodium chloride, calcium chloride, ammonium sulphate, etc.). This is the so-called salting-out effect. A further advantage is that the solubility of partially miscible organic solvents, such as ether, is considerably less in the salt solution, thus reducing the loss of solvent in extractions. 

The mono-methyl, ethyl and n-butyl ethers are inexpensive commercial products and are known as methyl carbitol, carbitol and butyl carbitol respectively. They are all completely miscible with water and are purified as already described for the cellosolves (10). The boiling points of the pure compounds are —... 

Di-alkyl ethers of ethylene glycol, ROCHjCHjOR. The dimethyl ether, b.p. 85°/760 mm., is miscible with water, is a good solvent for organic compounds, and is an excellent inert reaction medium. The diethyl ether (diethyl cdloaolve), b.p. 121-57760 mm., is partially miscible with water (21 per cent, at 20°). 

Diethylene dioxide is a very useful solvent for a variety of organic compounds its action is similar to that of ether but more pronounced. It is miscible with water in all proportions. Dioxan vapour is poisonous. 

The monoalkyl ethers with R = CHj, CjHj and C4H, , known respectively as methyl ceUoaolve, ceUosolve and hutyl cellosolve, are of great commercial value, particularly as solvents, since they combine the properties of alcohols and ethers and are miscible with water. Equally important compounds are the carbitols (monoalkyl ethers of diethyleneglycol) prepared by the action of ethylene oxide upon the monoethers of ethylene glycol ... 

A compound is most soluble in that solvent to which il is most closely related in structure. Thus re-hexane, which is sparingly soluble in water, dissolves in three volumes of methyl alcohol, is more soluble in anhydrous ethyl ilcohol, and is completely miscible with re-butyl and higher alcohols. As the chain length increases the compound tends to resemble the hydrocarbon more and more, and hence the solubihty increases. 

Physical Properties. Furfural [98-01-1] (2-furancarboxaldehyde), when freshly distilled, is a colorless Hquid with a pungent, aromatic odor reminiscent of almonds. It darkens appreciably on exposure to air or on extended storage. Furfural is miscible with most of the common organic solvents, but only slightly miscible with saturated aHphatic hydrocarbons. Inorganic compounds, generally, are quite insoluble in furfural. 

Butyrolactone is completely miscible with water and most organic solvents. It is only slightly soluble in aUphatic hydrocarbons. It is a good solvent for many gases, for most organic compounds, and for a wide variety of polymers. 

The overall extraction process is sometimes subdivided into two general categories according to the main mechanisms responsible for the dissolution stage (/) those operations that occur because of the solubiHty of the solute in or its miscibility with the solvent, eg, oilseed extraction, and (2) extractions where the solvent must react with a constituent of the soHd material in order to produce a compound soluble in the solvent, eg, the extraction of metals from metalliferous ores. In the former case the rate of extraction is most likely to be controUed by diffusion phenomena, but in the latter the kinetics of the reaction producing the solute may play a dominant role. 

CFC-113, CF2CICFCI2, or the hydrochlorofluorocarbons (HCFCs) such as HCFC-123, CF2CHCI2, HCFC-141b, or CH2CFCI2, are miscible in all proportions with the perfluoro compounds at 25°C. Typical solubiHty data are shown in Table 2. 

Alloys. GaUium has complete miscibility in the hquid state with aluminum, indium, tin, and zinc. No compounds are formed. However, these binary systems form simple eutectics having the following properties ... 

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