Ethanol dissolved in water

Ethanol is a polar molecule, and it is miscible with water that is, it mixes freely with water in all proportions. Ethanol has an O—H group that forms hydrogen bonds with water molecules. When ethanol dissolves in water, it forms new ethanol-water hydrogen bonds to replace the water-water and ethanol-ethanol hydrogen bonds that are broken ... 

Ethanol, also known as ethyl alcohol, is a typical covalent compound. It is a liquid at room temperature but evaporates readily into the air. Ethanol bolls at 78°C and freezes at -114°C. Unlike many covalent compounds, ethanol dissolves in water. In fact, ethanol sold in stores as rubbing alcohol contains water. 

Like dissolves like is an extremely useful rule of thumb. Structurally similar molecules associate with a similar intermolecular interaction. Thus, a molecule in the liquid can be substituted by a structurally similar molecule, without a major change in intermolecular interactions. Ethanol dissolves in water because major interactions holding water molecules to each other and those of the ethanol are very similar, hydrogen bond interactions. On the other hand, water and carbon tetrachloride make a biphase system. The carbon tetrachloride molecules are cast aside because they cannot make enough hydrogen bonding interaction with water molecules to hold the molecules in the water phase. Thus, the carbon tetrachloride molecules hold themselves in the other phase by van der Waals interaction. 

The Attractions Broken and Formed When Ethanol Dissolves in Water... 

Figure 20,6 The small increase in entropy when ethanol dissolves in water. Pure ethanol (A) and pure water (B) have many intermolecular H bonds. C, In a solution of these two substances, the molecules form H bonds to one another, so their freedom of motion does not change significantly. Thus, the entropy increase is relatively small and is due solely to random mixing.

Figure 20.8 The small increase in entropy when ethanol dissolves in water, in pure ethanol (A) and...

Suppose we place the apparatus in a solution of a molecular compound dissolved in water, as in Active Figure 9.2(a), which shows drinking alcohol (ethanol) dissolved in water. Nothing happens. But if the liquid is a solution of an ionic compound, the bulb glows brightly, as in Active Figure 9.2(b), which shows copper(II) chloride dissolved in water. 

Diethyl oxalate (29.2 g, 0.20mol) and 4-bromo-2-nitrotoluene (21.6 g, O.lOmol) were added to a cooled solution of sodium cthoxide prepared from sodium (4.6 g, 0.20 mol) and ethanol (90 ml). The mixture was stirred overnight and then refluxed for 10 min. Water (30 ml) was added and the solution refluxed for 2h to effect hydrolysis of the pyruvate ester. The solution was cooled and concentrated in vacuo. The precipitate was washed with ether and dried. The salt was dissolved in water (300 ml) and acidified with cone. HCl. The precipitate was collected, washed with water, dried and recrystallizcd from hexane-EtOAc to give 15.2 g of product. 

International Specialty Products (ISP) suppHes ethyl, isopropyl, and -butyl half-esters of PMVEMA as 50% solutions in ethanol or 2-propanol. Typical properties are shown in Table 8. These half-esters do not dissolve in water but are soluble in dilute aqueous alkaU and in aqueous alcohoHc amine solutions. The main appHcation for the half-esters is in hairsprays where they combine excellent hair-holding properties at high humidity without making the hair stiff or harsh. These half-esters are easily removed during shampooing, have a very low order of toxicity, and form tack-free films that exhibit good gloss, luster, and sheen (see Hair preparations). 

The most versatile derivative from which the free base can be readily recovered is the picrate. This is very satisfactory for primary and secondary aliphatic amines and aromatic amines and is particularly so for heterocyclic bases. The amine, dissolv in water or alcohol, is treated with excess of a saturated solution of picric acid in water or alcohol, respectively, until separation of the picrate is complete. If separation does not occur, the solution is stirred vigorously and warmed for a few minutes, or diluted with a solvent in which the picrate is insoluble. Thus, a solution of the amine and picric acid in ethanol can be treated with petroleum ether to precipitate the picrate. Alternatively, the amine can be dissolved in alcohol and aqueous picric acid added. The picrate is filtered off, washed with water or ethanol and recrystallised from boiling water, ethanol, methanol, aqueous ethanol, methanol or chloroform. The solubility of picric acid in water and ethanol is 1.4 and 6.23 % respectively at 20°. 

Amines can also be purified via their salts, e.g. hydrochlorides. A solution of the amine in dry toluene, diethyl ether, dichloromethane or chloroform is saturated with dry hydrogen chloride (generated by addition of concentrated sulfuric acid to dry sodium chloride, or to concentrated HCl followed by drying the gas through sulfuric acid, or from a hydrogen chloride cylinder) and the insoluble hydrochloride is filte off and dissolved in water. The solution is made alkaline and the amine is extracted, as above. Hydrochlorides can also be prepared by dissolving the amine in ethanolic HCl and adding diethyl ether or petroleum ether. Where... 

Eosin Y (as di-Na salt) [17372-87-1] M 691.9. Dissolved in water and ppted by addition of dilute HCl. The ppte was washed with water, crystd from ethanol, then dissolved in the minimum amount of dilute NaOH soln and evaporated to dryness on a water-bath. The purified disodium salt was then crystd twice from ethanol [Parker and Hatchard Trans Faraday Soc SI 1894 7967]. 

Absorption is widely used as a raw material and/or product recovery technique in separation and purification of gaseous streams containing high concentrations of VOC, especially water-soluble compounds such as methanol, ethanol, isopropanol, butanol, acetone, and formaldehyde. Hydrophobic VOC can be absorbed using an amphiphilic block copolymer dissolved in water. However, as an emission control... 

The residual oil was stirred and refluxed with sodium hydroxide (75 ml of 5N), water (45 ml) and 95% ethanol (120 ml). Within a few minutes a sodium salt separated and after 1 hour the solid was collected, washed with ethanol, dissolved in hot water and acidified with dilute hydrochloric acid to give the methyl malonic acid which was collected and dried in vacuo MP 177° to 180°C (dec.). 

This hydrochloride, on being dissolved in water and hydrogenated with hydrogen and a nickel catalyst, gave a good yield of hydrochloride of hydroxy-4 -phenyl-1-amino-2-ethanol melting, after crystallization from a mixture of ethyl alcohol and butanone-2, at from 177° to 179°C with decomposition. 

The reaction mixture Is stirred overnight at room temperature and filtered to remove the sodium chloride. The filtrate is stripped in vacuo and the crude ester (literature reports MP 48°C) is dissolved in 150 ml of ethanol 2B grams (0.70 mol of sodium hydroxide in 90 ml of water Is added and the solution is refluxed for 2 hours. After removal of the ethanol in vacuo the residue Is dissolved in water and extracted twice with ether. Dissolved ether Is removed from the aqueous solution in vacuo and it Is acidified to pH 2 with concentrated hydrochloric acid. 

A solution of 35.4 g of 1 -bromohexanone-5 in 200 ml of ethanol was gradually mixed at the reflux temperature with vigorous stirring with 39.7 g of theobromine-sodium in 100 ml of water. After 3 hours reflux the unreacted theobromine was filtered off with suction, the fil-trete was evaporated to dryness, the residue was dissolved in water and the solution was extracted with chloroform. The chloroform was distilled off and 1-(5 -oxohexyl)-3,7-dimethyl-xanthine was obtained as residue after recrystellization from isopropanol, it melted at 102°C to 103°C (about 25% yield, calculated on the reacted theobromine). 

Pipethanate hydrochloride Is dissolved in water and the solution is made alkaline by adding 10% sodium hydroxide solution. The crystals that are separated are filtered off and recrystallized from dilute ethanol. The monohydrate thereby obtained is dehydrated at 100°C under reduced pressure for 20 minutes. The products that are now in the form of a syrup due to loss of water of crystallization are further dehydrated for 2 days in a desiccator over phosphorus pentoxide whereupon the anhydrous pipethanate is obtained. 

The hydrogen sulfate was dissolved in water and the pH of the solution was adjusted to 5.6 (pH-meter) with 0.1 N sodium hydroxide solution. The water solution was evaporated to dryness and the residue dried with absolute ethanol/benzene and once more evaporated to dryness. The remaining crystal mixture was extracted in a Soxhiet extraction apparatus with absolute methanol. From the methanol phase the sulfate of 1-(3, 5 -dihydroxyphenyl)-2-(t-butylaminoj-ethanol crystallized. Melting point 246°C to 248°C. 

The requisite intermediate, ethyl 4-dimethylaminocyclohexylcarboxylate is prepared as follows 33 g of ethyl p-aminobenzoate dissolved in 300 cc of absolute ethanol containing 16.B cc of concentrated hydrochloric acid is hydrogenated at 50 pounds hydrogen pressure in the presence of 2 g of platinum oxide. The theoretical quantity of hydrogen is absorbed in several hours, the catalyst removed by filtration and the filtrate concentrated to dryness in vacuo. The residue Is dissolved in water, made alkaline with ammonium hydroxide and extracted with chloroform. After removal of the solvent, the residual oil is distilled to yield ethyl 4-aminocyclohexylcarboxylate, boiling point 114°C to 117°C/10 mm. 

In the cells discussed in Sec. 57 the solvent in every case was water. But in this chapter we shall discuss cells placed back to back, where one solution contains a solute dissolved in water, while the other contains the same solute dissolved in ethanol, or in methanol, or in a methanol-water mixture. When, for example, a hydrogen electrode containing IIC1 dissolved in ethanol is coupled to a Ag/AgCl electrode, also containing HC1 dissolved in ethanol, the cell may be written... 

Methyl yellow, neutral red, and Congo red. Dissolve 1 g of the indicator in 1 L of 80 per cent ethanol. Congo red may also be dissolved in water. 

A weighed portion of the AOS sample is dissolved in water and ethanol containing a small amount of n-decane and the mixture is shaken with petroleum spirit. The organic phase is subjected to GC using a 2 m x 10 mm packed column of 5% carbowax 20M on Chromorb T applying the following conditions ... 

There are some synthetic protocols that use a sonochemical approach to obtain magnetic NPs. Dang and co-workers demonstrated that ultrasonic irradiation of Fe (OH)2 dissolved in water [102] or water-ethanol [103, 104] can lead to Fe304 NPs. Recently, it has been reported that Fe304 [105, 106] or y-Fc203 [107] NPs with a controlled size distribution can be obtained by electroprecipitation in aqueous [105,... 

The platinum asbestos is removed by filtration and the product which has deposited on this catalyst is dissolved in water. Alcohol is added to the combined filtered solution and washings, and the mixture is cooled with ice to precipitate the product. A second crop of crystals may be obtained by concentrating the solution under vacuum at room temperature, then cooling and adding hydrochloric acid until the pH is below 1. The crystals are thoroughly washed with ethanol. 

Fig. 3 Prepared ZnO QDs embedded in Si02 matrix under (a) ordinary and (b) UV (365 nm excitation) lamps. (A) Solid samples, (B) samples dissolved in ethanol, and (C) samples dissolved in water. Photographs were taken with a digital camera just after completion of synthesis, (c) TEM Image of symmetrically dispersed ZnO QDs embedded in Si02 matrix. (Figure adapted from [40])...

Precipitate the sample to remove unreacted biotinylation reagent by adding 0.1 M potassium acetate and ethanol (1 2 ratio). Centrifuge and wash the biotinylated DNA pellet with ethanol, then dry it under nitrogen. The purified sample may be dissolved in water or buffer. 

Benzylamine (53.5 g, 0.5 mol) and crystalline phosphorous acid (82 g, 1.0 mol) were dissolved in water (100 ml), concentrated hydrochloric acid (100 ml) was added, and the mixture was heated to reflux. Over the course of 1 h, 37% aqueous formaldehyde (160 ml, 2.0 mol) was added dropwise, and the reaction mixture was maintained at reflux for another hour. After cooling, the solvent was evaporated, and the residual syrup was dissolved in hot ethanol. Upon cooling, the crude benzyliminodimethylenediphosphonic acid precipitated and was recrystallized from hot dilute hydrochloric acid to give the pure material (127 g, 85.7%) of mp 248°C, which exhibited analytical data in accord with the proposed structure. 

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