An introduction to the carbon compounds / by R.H. Adie.

  • Adie, R. H. (Richard Haliburton)
Date:
[1899]
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to the carbon compounds / by R.H. Adie. Source: Wellcome Collection.

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    and water, and cupric hydroxide, wiiiclL splits off water wlien warmed. We can now understand why phosphorus pentachloride substitutes the oxygen atom by two chlorine atoms, since the oxygen atom represents two hydroxy] groups. 64. Aldehyde with its two hydroxy! groups has the pro- perties of a metallic peroxide, and can unite both with a weak acid and a weak base; thus it combines (i) with ammonia forming a clear crystalline compound, aldehyde ammonia, and (ii) with hydrocyanic acid forming a hydroxy cyanide. Equations may be given, (i) OH.,CH(OH)^ + NH3 = CH3CH(0H)NH, + H,0 (ii) CH;CH(OH)j + HON = CH3CH(0H)CN + H,0 65. Starting with methyl alcohol instead of ethyl, it is oxidised in the same way to the aldehyde of the lowest possible carbon content, formaldehyde or methyl aldehyde, represented by the formulae H-CHO or HCH(0H)2_ This body is readily formed by the oxidation of methyl alcohol by free oxygen under the influence of platinum, but its special interest is connected with the probability that it is the first product of reduction of carbonic acid by the green plant, which may perhaps be represented by the equation CO(OH),. + H,0 = HCH(0H)3 + 0, Its properties are similar to those of aldehyde. 66. Chloral is prepared by passing chlorine through alcohol for a long time. The resulting liquid is distilled, mixed with water, and choral hydrate, CCI3CHO, HjO or CCl3CH(0H),, is crystallised out. Chloral hydrate is a colourless crystalline solid with_ a faint smell, which is more pungent on warming. It dis- solves in water, and is readily acted on by caustic alkahes with separation of chloroform. jjxp. 31.—Take a few crystals of chloral hydrate and dissolve them in water in a test tube. Add caustic potash, the solution turns milky and drops are soon noticed with the characteristie smell of chloroform.
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