Ethyl alcohol refractive index

Dichloroacetic acid [79-43-6] (CI2CHCOOH), mol wt 128.94, C2H2CI2O2, is a reactive intermediate in organic synthesis. Physical properties are mp 13.9°C, bp 194°C, density 1.5634 g/mL, and refractive index 1.4658, both at 20°C. The Hquid is totally miscible in water, ethyl alcohol, and ether. Dichloroacetic acid K = 5.14 X 10 ) is a stronger acid than chloroacetic acid. Most chemical reactions are similar to those of chloroacetic acid, although both chlorine... 

Ethyl Benzoate.—This ester has not been found, so far, to occur naturally in essential oils. It has, however, been prepared by synthetic processes, for example, by condensing ethyl alcohol with benzoic acid by means of dry hydrochloric acid gas. Its odour is very similar to that of methyl benzoate (q.v.), but not quite so strong. It is an oil of specific gravity I OfilO, refractive index 1 5055, and boiling-point 213° at 745 mm. It is soluble in two volumes of 70 per cent, alcohol. 

Ethyl Cinnamate.—The cinnamic ester of ethyl alcohol is a natural constituent of a few essential oils, including camphor oil and storax. It is formed synthetically by condensing cinnamic acid and ethyl alcohol by dry hydrochloric acid gas. It has a soft and sweet odour, and is particularly suitable for blending in soap perfumes. It is an oil at ordinary temperatures, melting at 12°, and boiling at 271°. Its specific gravity is 1 0546, and its refractive index 1 5590. 

The free oil can be determined by an ion exchange HPLC technique. A solution of the sample in ethyl alcohol is analysed by high-performance ion exchange chromatography using a specially prepared ion exchange resin stationary phase, ethanol mobile phase, and differential refractive index detection. 

Ethyl Alcohol occurs as a clear, colorless, mobile liquid. It is miscible with water, with ether, and with chloroform. It boils at about 78° and is flammable. Its refractive index at 20° is about 1.364. 

References are appended to investigations of the optical properties16 of the crystalline forms to such properties of the aqueous solution as vapour-pressure,17 density,18 molecular depression of the freezing-point,19 electric conductivity,20 and index of refraction 21 and to the solubility in ethyl alcohol.22... 

As pointed out by Skrabal and Schiffrer [173], the rate-determining step must be in the transition from acetal to hemiacetal because the rate coefficient for the hydrolysis of methyl ethyl formal is equal to the mean value of those for the hydrolyses of dimethyl formal and diethyl formal. Wolf and Hero Id [174] supplied more direct evidence on this matter. They found that the UV absorption bands of aldehydes slowly decrease in alcoholic solutions. This indicates that a reaction takes place. The product of the reaction immediately splits off aldehyde under the conditions of a bisulfite titration, therefore it cannot be acetal and it must be hemiacetal. Acetals are much more stable, and they are not hydrolyzed in a bisulfite titration. A quantitative kinetic study of the reaction of aldehyde with alcohol was carried out by Lauder (175] with the aid of dilatometric and refractive index measurements. He observed that hemiacetal is formed in a relatively fast reaction which is followed by a slow reaction leading to acetal. 

In this project, distinguishing properties of the 10 organic liquids should be observed (Part A) and unknowns subsequently identified (Part B) according to an SOP which I wrote for this. The properties are (1) water miscibility, (2) density, (3) viscosity, (4) refractive index, and (5) odor. The 10 organic liquids are acetone, methanol, ethanol, isopropyl alcohol, heptane, cyclohexane, toluene, methyl ethyl ketone, butanol, and ethyl acetate. 

Yellow prisms from propylene oxide or petr ether. Solvated crystals from more polar solvents, such as methanol or ethyl formate, mp 62-64°. Distills at 120-125" at 5 x lO-3 mm pressure, nj 1.6410 (calculated from refractive indexes of 20-70% solas in mineral oil), uv max 324-325 nm (E 1835) Baxter, Robeson, J. Am. Chem. Soc. 64, 2407 (1942+ Practically insol in water or glycerol sol in abs alcohol, methanol, chloroform, ether, fats and oils. Ultraviolet light inactivates vitamin A and its solns which exhibit a characteristic green fluorescence. The free alcohol is sensitive to air-oxidation, but oil solns of it are quite stable. Esters of vitamin A are more stable to oxidation. LDn (10 day) in mice (mg/kg) 1510 i.p. 2570 orally (Kamm). 

Figure 7. Temperature dependence of the refractive index of solvents a) Methylbenzyl alcohol b) Butyl diglycol c) Butyl glycol d) Butanol e) Butyl acetate f) Ethyl acetate...

Table 6.23 Index of Refraction of Ethyl Alcohol-Water Mixtures at SO F (30)...

Ethyl alcohol (1869) (alcohol, ethanol, and grain alcohol) n. An alcohol used, in denatured form, as a solvent for ethyl cellulose, polyvinyl acetate, and polyvinyl butyrate. The industrial grade of undenatured alcohol usually contains 5 wt% water. Properties bp, 78°C Sp gr. 0.7938/15°C refractive index, 1.367. The pure compound is called absolute alcohol. 

Niohe oil, or ethyl benzoate, the ester obtained from ethyl alcohol and benzoic acid, and having the specific gravity at 15° C., 1 094-1 095 refractive index at 20° C., 1 5167 boiling point, 196 5°-198° C. soluble in 1 5 volumes of 70 per cent, alcohol. 

Ethyl Acetate n (1874) CH3COOC2H5. A colorless liquid made by heating acetic acid and ethyl alcohol in the presence of sulfuric acid, then distilling. It is a powerful solvent for ethyl cellulose, polyvinyl acetate, cellulose acetate-butyrate, acrylics, polystyrene, and coumarone-indene resins. It is also used in flexographic and rotogravure inks. Although it is highly flammable, it is the least toxic of common industrial solvents. Properties bp, 77°C sp gr, 0.—901/20°C flp. 0.56°C (31°F) refractive index, 1.373 vp, 77 mm Hg/20°C. Also known as Acetic Ether and Acetic Ester. 

For a pure mixture of ethyl and methyl alcohols in aqueous solution, the components may be estimated by determination of the density and refractive index of the solution and consultation of published tables. 

Adams and Nicholls state that if a distillate contains less than about 17 per cent of apparent proof spirit, the specific gravity and index of refraction for the low alcohols and acetone are very nearly a linear function of the quantities of each in solution. If the apparent proof spirit be found, then multiplying by the factor 0 585 for methyl alcohol and by 0 573 for ethyl alcohol, for each 1 per cent proof will give the percentage by volume, not differing by more than 0-1 per cent from the correct value. 

Flash pt 125°C (275°F). Miscible with water, methanol, alcohol, acetone, and ethyl acetate. Soluble in ether (25°C) 11% w/w. Limited solubility in benzene, trichloroethylene, methylene chloride, petrol ether, and heptane. LD50 orally in rats 5.89g/kg (Smyth). Melting point mp — 18°C Boiling point bp76o 239°C bp3.o 120°C. Flash point Flash pt 125°C (275°F). Index of refraction 1.4499. 

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