Text-book of chemistry

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1919 Excerpt: ... passes over between 94 and 99 being collected. It sometimes happens that chloral in contact with H2S04 is converted into a modification, insoluble in H20, known as metachloral; when this occurs it is washed with H20, dried and heated to 180, when it is converted into the soluble variety, which distils over. The formation of chloral from alcohol does not progress according to the simple equation: CH3.CH20H+4Cl2=:CCl2.CH0-f5HCl but passes through several stages. First, the alcohol is oxidized to aldehyde: CH3.CH20H+Cl2=CH3.CH0+2HCl This reacts with alcohol to produce acetal: CH3.CH0+2CH3.CH20H=CH3.CH(0C2H5)2+H20 This is then converted into trichloracetal: CH3CH (0C2H5) 2+3Cl2=CCl2.CH (0C2H5) 2+3HCl This, by the action of the hydrochloric acid formed in the last reaction, yields chloral alcoholate and ethyl chloride: Cci3.ch(0c2h5)2+hci=cci3.ch/ohh+c2h5ci And from the former chloral is liberated by sulphuric acid: CCl3.CH.c»H. +H2S04=CCl2.CH0+(C2H5) HS04+H20 Chloral is a colorless liquid, unctuous to the touch; has a penetrating odor and an acrid, caustic taste; sp. gr. 1.502 at 18, boils at 97, very soluble in water, alcohol, and ether; dissolves Cl, Br, I, S, and P. Its vapor is highly irritating. It distils without alteration. Although chloral has not been obtained by the direct substitution of Cl for H in aldehyde, its reactions show it to be an aldehyde. It forms crystalline compounds with the bisulphites; it reduces solutions of silver nitrate in the presence of NH3; with nascent H it regenerates aldehyde; oxidizing agents convert it into trichloracetic acid. Alkaline solutions decompose it with formation of chloroform and a formate: CCl2.CH0+K0H=CHCl2+H.C00K With a small quantity of H20 chloral forms a solid, crystalline hydrate, heat being at the...