Journal of the Chemical Society, 1905, Vol. 87

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Excerpt from Journal of the Chemical Society, 1905, Vol. 87: TransactionsThe aminoazo-compound or its sulphate (meldola and Williams, loc. Cit.) is suspended in dilute sulphuric acid, and to the well-cooled solu tion a strong solution of sodium dichromate is added drop by drop, until a distinct orange colour indicates the presence of an excess of the reagent. The sulphate of the azo-base at first dissol'ves, and after some hours yellow, scaly crystals are deposited. It is best to keep the beaker containing the solution in melting ice during the oxidation, and to employ a cold saturated solution of sodium dichromate. The crystalline deposit is collected, washed with water, and finally with alcohol to remove quinone. When dry, the diazonium chromate is very stable if kept in the dark. On exposure to light, it gradually becomes brown. The salt can be dissolved in boiling glacial acetic acid, and the solution, when rapidly cooled, deposits the unaltered compound in the form of dense orange scales. The exploding point of the pure salt is 144 - 1480 5 the explosion is not particularly Violent, and is followed by a cloud of woolly chromium sesquioxide.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.