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Purchasers can download a free scanned copy of the original book (without typos) from the publisher. 1876. Excerpt: ... it, by gentle ignition in a current of hydrogen gas, as in a. The brown sulphide of molybdenum changes in this process to the gray bisulphide (H. Rose;. e. F. Pisani* gives the following method for estimating molybdic acid volumetrically. Digest the molybdic acid with hydrochloric acid and zinc, dissolving any precipitate which may form from want of acid and also the excess of zinc. Convert -the solution of sesquioxide of molybdenum thus obtained into molybdic acid by standard permanganate of potash. The brown color of the solution turns first green, and then disappears. RAMMELSBERot confirms the statements of Pisani. II. DETERMINATION OF ACIDS IN COMPOUNDS CONTAINING ONLY ONE ACID, FREE OR COMBINED;--AND SEPARATION OF ACIDS FROM BASES. FIRST GROUP. First Division. Arsenious Acid--Arsenic Acid--Chromic Acid--(Selenious Acid, Sulphurous and Hyposulphurous Acids, lodic Acid). SS 129- 1. Arsenious And Arsenic Acids. These have been already treated of among the bases (SS 127) on account of their behavior with sulphuretted hydrogen; they are merely mentioned here to indicate the place to which they properly belong. The methods of separating them from the bases will be found in Section V. SS 130. 2. Chromic Acid. I. Determination. Chromic acid is determined either as sesquioxide of chromium, chrosnate of lead, orchromate of baryta. But it may be estimated also from the quantity of carbonic acid disengaged by its action upon oxalic acid in excess, and also by volumetric analysis. In employing the first method, it must be borne in mind that 1 eq. sesquioxide of chromium corresponds to 2 eq. chromic acid. a. Determination as Sesquioxide of Chromium. a. The chromic acid is reduced to the state of sesquioxide, and the amount of the latter determined (SS 106). The reduction is e...
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