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Outlines of the course of qualitative analysis followed in the Giessen laboratory / By Henry Will ; With a preface by Baron Liebig.

  • Heinrich Will
Date:
1846
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of the course of qualitative analysis followed in the Giessen laboratory / By Henry Will ; With a preface by Baron Liebig. Source: Wellcome Collection.

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    GROUP III. METALS WHICH ARE NOT PRECIPITATED BY HYDROSULPHURIC ACID FROM THEIR SOLUTIONS CONTAINING FREE MINERAL ACID, BUT WHICH ARE THROWN DOWN BY SULPHIDE OF AMMONIUM, PARTLY AS OXIDES, PARTLY AS SULPHIDES, FROM THEIR NEUTRAL SOLUTIONS. This great group consists of the following fifteen metals : Aluminum, | glucinum, thorium, yttrium, cerium, zirconium | chromium, [titanium, tantalum * | eee iron, zinc, [uranium } cobalt and nickel. us The oxides of the nine first mentioned metals do not give up their oxygen for the sulphur of the hydrosulphuric acid HS ; they are thrown down therefore as oxides by the action of the ammonia contained in the sulphide of ammonium with evolution of hydrosulphuric acid, ex. gr. Al,O,,380, +83NH,S+38HO=AI,0, +3(NH,0,SO,) +3HS. These are, with the exception of chromium, [titanium and tantalum] the earths proper. The oxides of the last six metals are decomposed in their neutral solutions by the action of hydro- sulphuric acid, water being formed, and a sulphide insoluble in water, ex. gr. | MnO,SO, + HS = Mn8S+ HO, S8O,. These metals decompose water in the presence of acids, with evolution of hydrogen; their sulphides disengage, under the same circumstances, hydrosulphuric acid: sulphide of nickel, and sulphide of cobalt, however, are only with difficulty soluble in dilute mineral acids. In consequence of their behaviour with the common reagents, the oxides and sulphides of the metals of this group may be arranged under the following subdivisions. 1. [Oxides which are either quite insoluble in hydrochloric acid, or which may by boiling be precipitated from their acid solution: tetanic acid, tantalic acid. | * We might add to these lanthanum, and didymiwm, erbiwm, and terbiwm, which respectively resemble cerium and yttrium, also niobium, which was formerly mistaken for tantalum. We have omitted these, as their chemical reactions are not yet sufficiently known.
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