Solubility hydrocarbons/water

The solubility of water in hydrocarbons increases strongly with temperature. 

The hydrocarbons are in general only slightly soluble in water. The solubility depends especially on the chemical nature of the hydrocarbons. 

The solubility of hydrocarbon liquids from the same chemical family diminishes as the molecular weight increases. This effect is particularly sensitive thus in the paraffin series, the solubility expressed in mole fraction is divided by a factor of about five when the number of carbon atoms is increased by one. The result is that heavy paraffin solubilities are extremely small. The polynuclear aromatics have high solubilities in water which makes it difficult to eliminate them by steam stripping. 

In the standard method, the metal enclosure (called the air chamber) used to hold the hydrocarbon vapors is immersed in water before the test, then drained but not dried. This mode of operation, often designated as the wet bomb" is stipulated for all materials that are exclusively petroleum. But if the fuels contain alcohols or other organic products soluble in water, the apparatus must be dried in order that the vapors are not absorbed by the water on the walls. This technique is called the dry bomb" it results in RVP values higher by about 100 mbar for some oxygenated motor fuels. When examining the numerical results, it is thus important to know the technique employed. In any case, the dry bomb method is preferred. 

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. 

Solubility in Water A familiar physical property of alkanes is contained m the adage oil and water don t mix Alkanes—indeed all hydrocarbons—are virtually insoluble m water In order for a hydrocarbon to dissolve m water the framework of hydrogen bonds between water molecules would become more ordered m the region around each mole cule of the dissolved hydrocarbon This increase m order which corresponds to a decrease m entropy signals a process that can be favorable only if it is reasonably... 

Hydrophilic (Section 19 5) Literally water loving a term applied to substances that are soluble in water usually be cause of their ability to form hydrogen bonds with water Hydrophobic (Section 19 5) Literally water hating a term applied to substances that are not soluble in water but are soluble in nonpolar hydrocarbon like media Hydroxylation (Section 15 5) Reaction or sequence of reac tions in which an alkene is converted to a vicinal diol Hyperconjugation (Section 4 10) Delocalization of a electrons... 

The methyl and ethyl esters of cyanoacetic acid are slightly soluble ia water but are completely miscible ia most common organic solvents including aromatic hydrocarbons. The esters, like the parent acid, are highly reactive, particularly ia reactions involving the central carbon atom however, the esters tend not to decarboxylate. They are prepared by esterification of cyanoacetic acid and are used principally as chemical iatermediates. 

Physical properties are Hsted in Table 2. Butenediol is very soluble in water, lower alcohols, and acetone. It is nearly insoluble in aUphatic or aromatic hydrocarbons. 

The cobalt catalyst can be introduced into the reactor in any convenient form, such as the hydrocarbon-soluble cobalt naphthenate [61789-51 -3] as it is converted in the reaction to dicobalt octacarbonyl [15226-74-17, Co2(CO)g, the precursor to cobalt hydrocarbonyl [16842-03-8] HCo(CO)4, the active catalyst species. Some of the methods used to recover cobalt values for reuse are (11) conversion to an inorganic salt soluble ia water conversion to an organic salt soluble ia water or an organic solvent treatment with aqueous acid or alkah to recover part or all of the HCo(CO)4 ia the aqueous phase and conversion to metallic cobalt by thermal or chemical means. 

The physical and chemical properties are less well known for transition metals than for the alkaU metal fluoroborates (Table 4). Most transition-metal fluoroborates are strongly hydrated coordination compounds and are difficult to dry without decomposition. Decomposition frequently occurs during the concentration of solutions for crysta11i2ation. The stabiUty of the metal fluorides accentuates this problem. Loss of HF because of hydrolysis makes the reaction proceed even more rapidly. Even with low temperature vacuum drying to partially solve the decomposition, the dry salt readily absorbs water. The crystalline soflds are generally soluble in water, alcohols, and ketones but only poorly soluble in hydrocarbons and halocarbons. 

Physical properties of glycerol are shown in Table 1. Glycerol is completely soluble in water and alcohol, slightly soluble in diethyl ether, ethyl acetate, and dioxane, and insoluble in hydrocarbons (1). Glycerol is seldom seen in the crystallised state because of its tendency to supercool and its pronounced freesing point depression when mixed with water. A mixture of 66.7% glycerol, 33.3% water forms a eutectic mixture with a freesing point of —46.5°C. 

Hydroxypivalyl hydroxypivalate is soluble in most alcohols, ester solvents, ketones, and aromatic hydrocarbons. It is partially soluble in water (6). 

Glycohc acid is soluble ia water, methanol, ethanol, acetone, acetic acid, and ethyl acetate. It is slightly soluble ia ethyl ether and spatingly soluble ia hydrocarbon solvents. 

Cyclodienes. These are polychlorinated cycHc hydrocarbons with endomethylene-bridged stmctures, prepared by the Diels-Alder diene reaction. The development of these insecticides resulted from the discovery in 1945 of chlordane, the chlorinated adduct of hexachlorocyclopentadiene and cyclopentadiene (qv). The addition of two Cl atoms across the double bond of the ftve-membered ring forms the two isomers of chlordane [12789-03-6] or l,2,4,5,6,7,8,8-octachloro-2,3,3t ,4,7,7t -hexahydro-4,7-methano-lJT-indene, QL-trans (mp 106.5°C) and pt-tis (32) (mp 104.5°C). The p-isomerhas signiftcantiy greater insecticidal activity. Technical chlordane is an amber Hquid (bp 175°C/267 Pa, vp 1.3 mPa at 25°C) which is soluble in water to about 9 fig/L. It has rat LD qS of 335, 430 (oral) and 840, 690 (dermal) mg/kg. Technical chlordane contains about 60% of the isomers and 10—20% of heptachlor. It has been used extensively as a soil insecticide for termite control and as a household insecticide. 

The nitro alcohols generally are soluble in water and in oxygenated solvents, eg, alcohols. The monohydtic nitro alcohols are soluble in aromatic hydrocarbons the diols are only moderately soluble even at 50°C at 50°C the triol is insoluble. 

Solubility. Poly(ethylene oxide) is completely soluble in water at room temperature. However, at elevated temperatures (>98° C) the solubiUty decreases. It is also soluble in several organic solvents, particularly chlorinated hydrocarbons (see Water-SOLUBLE polymers). Aromatic hydrocarbons are better solvents for poly(ethylene oxide) at elevated temperatures. SolubiUty characteristics are Hsted in Table 1. 

These compounds are highly soluble in water. AMP, AMPD, AEPD, and DMAMP are completely miscible in water at 20 °C the solubihty of AB is 250 g/100 mL H2O at 20°C. They are generally very soluble in alcohols, slightly soluble in aromatic hydrocarbons, and nearly insoluble in aliphatic hydrocarbons tris(hydroxymethy1)aminomethane [77-86-1] is appreciably soluble only in water (80 g/100 mL at 20°C) and methanol. 

Monobutylamines are easily soluble in water and hydrocarbons and can generally be steam distilled. These properties lead to uses in soaps for water and oil emulsions, and as corrosion inhibitors in steam boiler appHcations (see Corrosion and corrosion inhibitors Emulsions). Morpholine is also extensively used as a corrosion inhibitor in steam boiler systems. In addition, it is widely used as an intermediate in the production of delayed-action mbber accelerators. 

The heavy metal salts, ia contrast to the alkah metal salts, have lower melting points and are more soluble ia organic solvents, eg, methylene chloride, chloroform, tetrahydrofiiran, and benzene. They are slightly soluble ia water, alcohol, ahphatic hydrocarbons, and ethyl ether (18). Their thermal decompositions have been extensively studied by dta and tga (thermal gravimetric analysis) methods. They decompose to the metal sulfides and gaseous products, which are primarily carbonyl sulfide and carbon disulfide ia varying ratios. In some cases, the dialkyl xanthate forms. Solvent extraction studies of a large number of elements as their xanthate salts have been reported (19). 

Cyclosporin A forms white prismatic crystals from acetone and is only slightly soluble in water and saturated hydrocarbons, but is very soluble in methanol, ethanol, acetone, and diethyl ether. Optical and nmr data on cyclosporins and x-ray crystallographic data on cyclosporin A and an io do derivative have been reviewed (273,275). 

Caprolactam, mol wt 113.16, is a white, hygroscopic, crystalline soHd at ambient temperature, with a characteristic odor. It is very soluble in water and in most common organic solvents and is sparingly soluble in high molecular weight aUphatic hydrocarbons. Molten caprolactam is a powerful solvent for polar and nonpolar organic chemicals. Selected physical properties and solubiUties of caprolactam are Hsted in Tables 1 and 2, respectively. 

The isomeric mixture is a colodess, mobile Hquid with a sweet, slightly irritating odor resembling that of chloroform. It decomposes slowly on exposure to light, air, and moisture. The mixture is soluble ia most hydrocarbons and only slightly soluble ia water. The cis—trans proportions ia a cmde mixture depend on the production conditions. The isomers have distinct physical and chemical properties and can be separated by fractional distillation. 

Water generally is used for gases fairly soluble in water, oils for light hydrocarbons, and special chemical solvents for acid gases such as CO9, SO9, and H9S. Sometimes a reversible chemical reaction will result in a veiy high solubility and a minimum solvent rate. Data on actual systems are desirable when chemical reactions are involved, and those available are referenced later under Absorption with Chemical Reaction. ... 

Hydrophobic (Section 19.5) Literally, water-hating a term applied to substances that are not soluble in water, but are soluble in nonpolar, hydrocarbon-like media. 

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