Alcohol atoms

A white solid, m.p. 178 C. Primarily of interest as a brominaling agent which will replace activated hydrogen atoms in benzylic or allylic positions, and also those on a carbon atom a to a carbonyl group. Activating influences can produce nuclear substitution in a benzene ring and certain heterocyclic compounds also used in the oxidation of secondary alcohols to ketones. 

Later findings have modified the rule, especially when the carbon atoms concerned are connected with carbonyl- or carboxyl-groups, but it still holds good for monohydric unsaturated alcohols. 

The fatty acids occur in nature chiefly as glycerides see fats), which constitute the most important part of the fats and oils, and as esters of other alcohols, the waxes. The naturally occurring fatty acids are mostly the normal straight-chain acids with an even number of carbon atoms. 

C, b.p. 156 C. The most important of the terpene hydrocarbons. It is found in most essential oils derived from the Coniferae, and is the main constituent of turpentine oil. Contains two asymmetric carbon atoms. The (- -)-form is easily obtained in a pure state by fractionation of Greek turpentine oil, of which it constitutes 95%. Pinene may be separated from turpentine oil in the form of its crystalline nitrosochloride, CioHigClNO, from which the ( + )-form may be recovered by boiling with aniline in alcoholic solution. When heated under pressure at 250-270 C, a-pinene is converted into dipentene. It can be reduced by hydrogen in the presence of a catalyst to form... 

With regards to the overall balance of combustion, the chemical structure of the motor or heating fuel, e.g., the number of carbon atoms in tbe chain and the nature of the bonding, does not play a direct role the only important item is the overall composition, that is, the contents of carbon, hydrogen, and — eventually— oxygen in the case of alcohols or ethers added to the fuel. 

Carbon dioxide is used in the manufacture of sodium carbonate by the ammonia-soda process, urea, salicyclic acid (for aspirin), fire extinguishers and aerated water. Lesser amounts are used to transfer heat generated by an atomic reactor to water and so produce steam and electric power, whilst solid carbon dioxide is used as a refrigerant, a mixture of solid carbon dioxide and alcohol providing a good low-temperature bath (195 K) in which reactions can be carried out in the laboratory. 

Iron(III) chloride forms numerous addition compounds, especially with organic molecules which contain donor atoms, for example ethers, alcohols, aldehydes, ketones and amines. Anhydrous iron(III) chloride is soluble in, for example, ether, and can be extracted into this solvent from water the extraction is more effective in presence of chloride ion. Of other iron(III) halides, iron(III) bromide and iron(III) iodide decompose rather readily into the +2 halide and halogen. 

Certain aliphatic compounds are oxidised by concentrated nitric acid, the carbon atoms being split off in pairs, with the formation of oxalic acid. This disruptive oxidation is shown by many carbohydrates, e.g., cane sugar, where the chains of secondary alcohol groups, -CH(OH)-CH(OH)-CH(OH)CH(OH)-, present in the molecule break down particularly readily to give oxalic acid. 

Fructose (V) under similar conditions gives first the phenylhydrazonc (Va) by the direct condensation of the >C 0 group of carbon atom 2 with one molecule of phenylhydrazine. The second molecule of phenylhydrazine then oxidises the primary alcohol group of carbon atom 1 to the -CHO group by removal of two atoms of hydrogen, which as before serve to reduce the phenyl-hydrazine to aniline and ammonia. The compound (Vb) which is thus produced then undergoes direct condensation with the third molecule of phenylhydrazine, giving the osazone of fructose, or fructosazone (Vc). 

Note. Formaldehyde is a special case. It reacts similarly, but a primary alcohol is necessarily produced. This alcohol, however, will always contain one carbon atom more than that obtained in Reaction (2). 

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... 

Aliphatic hydrocarbons can be prepared by the reduction of the readily accessible ketones with amalgamated zinc and concentrated hydrochloric acid (Clemmensen method of reduction). This procedure is particularly valuable for the prep>aration of hydrocarbons wdth an odd number of carbon atoms where the Wurtz reaction cannot be applied with the higher hydrocarbons some secondary alcohol is produced, which must be removed by repeated distillation from sodium. 

The student will doubtless be aware of the fact that methyl, ethyl, n-propyl and iso propyl alcohols are completely miscible with water. The solubilities of the higher aloohols decrease progressively as the carbon content increases. The solubilities of all types of alcohols with five carbon atoms or more are quite small. For the isomeric butyl alcohols the solubilities (g. per 100 g. of water at 20°) are n-butyl, 8 iso-butyl, 23 scc.-butyl, 13 ierl.-butyl, completely miscible. 

Place 204 g. (249-5 ml.) (2 gram mols) of dry n-hexyl alcohol in a 350 ml. Claisen flask with fractionating side arm. Introduce 5-75 g. (0-25 gram atoms) of clean sodium in small pieces and warm under reflux (as in Fig. Ill, 58, 1 but with dropping funnel omitted ) until all the sodium has reacted (ca. 2 hours). Introduce 39 g. (20 ml.) (0-25 gram... 

Phenol condenses with phthahc anhydride in the presence of concentrated sulphuric acid or anhydrous zinc chloride to yield the colourless phenolphthalein as the main product. When dilute caustic alkah is added to an alcoholic solution of phenolphthalein, an intense red colouration is produced. The alkali opens the lactone ring in phenolphthalein and forms a salt at one phenolic group. The reaction may be represented in steps, with the formation of a h3q)othetical unstable Intermediate that changes to a coloured ion. The colour is probably due to resonance which places the negative charge on either of the two equivalent oxygen atoms. With excess of concentrated caustic alkali, the first red colour disappears this is due to the production of the carbinol and attendant salt formation, rendering resonance impossible. The various reactions may be represented as follows ... 

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