Weight alcohol

The benzene is removed at atmospheric pressure, and the residue is distilled under reduced pressure from a 50-cc. Claisen flask. The fraction boiling at 89-91°/7 mm. consists of colorless benzyl alcohol weight 19 g. (89%). A small amount of higher-boiling material, benzyl benzoate, remains in the flask (with a 200% excess of aluminum isopropoxide in 200 cc. of isopropyl alcohol, the yield dropped to 65% and a larger high-boiling fraction resulted). 

The nitration reaction that consists in replacing a hydroxyl group by a nitro group is not often used. It is usually applied to tertiary alcohols. For example, tert-butyl alcohol (trimethylcarbinol) reacted with nitric acid to yield tert-nitro-butane in 10% yield in relation to the alcohol weight (Haitinger [4]) ... 

Per cent alcohol by volume Density at 2074° C Per cent alcohol weight Grams of alcohol per 100 ml Per cent alcohol volume Density at 2074° C Per cent alcohol by weight Grams of alcohol per 100 ml... 

Alcohol Weight Takent g Weight % Alcohol Peak Area A, cm Weight % Area Relalbe Re.spon c Factor F... 

Fig. 3.18 shows a typical force curve for an aqueous solution of an anionic surfactant and an alcohol (weight composition 7.2% sodium dodecyl sulfate, 17.5% 1-pentanol, 75.3% water), that forms a lamellar smectic A phase at room temperature and alignes homeotropically on bare mica [43]. The structural force is characterized by periodic damped oscillations, with... 

Corresponding values for proof, parts by vo ume of water and alcohol, weight % alcohol and specific gravity in air. 

The merging of the water melting peaks in system E is yet to be investigated, but it may be associated with the presence of more butanol molecules at the interface relative to system D [42]. The amount of alcohol present at the interface of microemulsion systems increases with the chain length of the oil. Thus, we evaluated [45] the molar ratio of alcohol to surfactant, NJNs, for the system water-Ci2(EO)8 + hexanol (1 l)-oil, using an equation derived by Kunieda et al. [90] for the determination of the surfactant/alcohol weight ratio at the interface (for systems present on the border between Winsor III and Winsor IV). For heptane, Na/Ns = 1.8 for decane, N /Ns = 2.4 and for hexadecane, N /Ns = 3.3. 

The polycondensation of di-isocyanates with polyhydric alcohols gives a wide range of polyurethanes which are used as artificial rubbers and light-weight foams, and have other important properties. Isocyanates are also used as modifiers in alkyd resins. ... 

They are colourless liquids with characteristic odours, and are prepared by the condensation of ketones with alkyl orthoformates in the presence of alcohols, or by the reaction of acetylenes with alcohols in presence of HgO and BF3. In some cases trichloroethanoic acid is used as the catalyst. They lose alcohol when heated and form vinyl ethers. Exchange of alcohol groups occurs when the ketals of the lower alcohols are boiled with alcohols of greater molecular weight. See acetals. 

The monomers used are second generation petrochemical products. The polymethacrylates are in fact copolymers based on methyl methacrylate and up to C20 molecular weight alcohol methacrylate. The properties of the additive are controlled based on the molecular ratio of these different monomers and their molecular weight. 

The type of behavior shown by the ethanol-water system reaches an extreme in the case of higher-molecular-weight solutes of the polar-nonpolar type, such as, soaps and detergents [91]. As illustrated in Fig. Ul-9e, the decrease in surface tension now takes place at very low concentrations sometimes showing a point of abrupt change in slope in a y/C plot [92]. The surface tension becomes essentially constant beyond a certain concentration identified with micelle formation (see Section XIII-5). The lines in Fig. III-9e are fits to Eq. III-57. The authors combined this analysis with the Gibbs equation (Section III-SB) to obtain the surface excess of surfactant and an alcohol cosurfactant. 

Method. A known weight of the alcohol is heated w ith a definite volume of a mixture of acetic anhydride and pyridine until acetylation is complete ... 

The excess of unchanged acetic anhydride is then hydrolysed by the addition of water, and the total free acetic acid estimated by titration with standard NaOH solution. Simultaneously a control experiment is performed identical with the above except that the alcohol is omitted. The difference in the volumes of NaOH solution required in the two experiments is equivalent to the difference in the amount of acetic add formed, i.e., to the acetic acid used in the actual acetylation. If the molecular weight of the alcohol is known, the number of hydroxyl groups can then be calculated. 

Note, (i) It fs clear that the molecular weight of the alcohol or phenol must be known before the above determinations are carried out. The molecular weight if unknown must be determined by one of the methods gii en on... 

Other pairs of liquids which exhibit an upper consolute temperature are methyl alcohol - cyclohexane (C.S.T. 49 -1° critical composition 29 per cent, by weight of methyl alcohol) isopentane - phenol (63 5° 51 per cent, of isopentane) and carbon disulphide - methyl alcohol (40-5° 80 per cent, of carbon disulphide). 

The developer is generally a solvent in which the components of the mixture are not too soluble and is usually a solvent of low molecular weight. The adsorbent is selected so that the solvent is adsorbed somewhat but not too strongly if the solvent is adsorbed to some extent, it helps to ensure that the components of the mixture to be adsorbed will not be too firmly bound. Usually an adsorbate adheres to any one adsorbent more firmly in a less polar solvent, consequently when, as frequently occurs, a single dense adsorption zone is obtained with light petroleum and develops only slowly when washed with this solvent, the development may be accelerated by passing to a more polar solvent. Numerous adsorbat are broken up by methyl alcohol, ethyl alcohol or acetone. It is not generally necessary to employ the pure alcohol the addition from 0 5 to 2 per cent, to the solvent actually used suffices in most cases. 

Absolute ethyl alcohol. Ethyl alcohol of a high degree of purity is frequently required in preparative organic chemistry. For some purposes alcohol of ca. 99 -5 per cent, purity is satisfactory this grade may be purchased (the absolute alcohol of commerce), or it may be conveniently prepared by the dehydration of rectified spirit with quicklime. Rectified spirit is the constant boiling point mixture which ethyl alcohol forms with water, and usually contains 95 6 per cent, of alcohol by weight. Wherever the term rectified spirit is used in this book, approximately 95 per cent, ethyl alcohol is to be understood. 

Absolute methyl alcohol. The synthetic methanol now available is suitable for most purposes without purification indeed, some manufacturers claim a purity of 99 85 per cent, with not more than 0 1 per cent, by weight of water and not more than 0 02 per cent, by weight of acetone. Frequently, however, the acetone content may be as high as 0 1 per cent, and the water content 0-5-1 per cent. 

To decide which component should be employed for the calculation of the yield of ethyl iodide, the weights of the reactants are first divided by the appropriate atomic or molecular weight in order to obtain the number of gram atoms or gram mols actually used. The equation shows that the alcohol and iodine react in the ratio of 5 5 or 1 1. Inspection of the results clearly shows that the alcohol is present in about 20 per... 

The melting points of these esters are usually much lower than those of the corresponding 3 5 dinitrobenzoates their preparation, therefore, offers no advantages over the latter except for alcohols of high molecular weight and for polyhydroxy compounds. The reagent is, however, cheaper than 3 5 dinitrobenzoyl chloride it hydrolyses in the air so that it should either be stored under light petroleum or be prepared from the acid, when required, by the thionyl chloride or phosphorus pentachloride method. 

Place a mixture of 0-5 g. of finely powdered thiourea, 0-5 g. of the alkyl halide and 5 ml. of alcohol in a test-tube or small flask equipped with a reflux condenser. Reflux the mixture for a j)eriod depending upon the nature of the halide primary alkyl bromides and iodides, 10-20 minutes (according to the molecular weight) secondary alkyl bromides or iodides, 2-3 hours alkyl chlorides, 3-5 hours polymethy lene dibromides or di-iodides, 20-50 minutes. Then add 0 5 g. of picric acid, boil until a clear solution is obtained, and cool. If no precipitate is obtained, add a few drops of water. RecrystaUise the resulting S-alkyl-iso-thiuronium picrate from alcohol. 

Pure bromoform is somewhat unstable and darkens on keeping it may be stabilised by the addition of 4 per cent, of its weight of ethyl alcohol or of a small quantity of diphenylamine. 

This separation utilises the fact that n-butyl alcohol is soluble in 50 per cent, sulphuric acid by weight, whilst n-butyl ether is only slightly soluble. 

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