Qualitative analysis / by William Briggs and R.W. Stewart.

  • William Briggs
Date:
1913
Catalogue details

Licence: Public Domain Mark

Credit: Qualitative analysis / by William Briggs and R.W. Stewart. Source: Wellcome Collection.

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    It is also soluble in caustic alkalies, forming an antimonite and a thioantimonite— 6 KOH + Sb2S3 = KgSbOg + KgSbSg + 3 H20. Potassium Potassium antimonite thioantimonite It is insoluble in ammonium carbonate, but dissolves in boiling strong HC1. Sb2S3 + 6 HC1 = 2 SbCl3 + 3 H2S. 2. Water produces a white milldness due to the pre¬ cipitate of antimony oxychloride, SbOCl—* SbCl3 + II20 = SbOCl + 2 HC1. The precipitate is easily soluble in tartaric acid [Dis¬ tinction from bismuth], forming antimonyl tartrate, (SbO)2 C4H406. SbOCl + C4HGOd =.(Sb0)2C4H406 + 2 HC1. 3. If a piece of platinum-foil and then a strip of zinc be dropped into a solution of antimony acidulated with HC1, so that the metals touch one another, a brown or black him (metallic antimony) will coat the platinum : free nitric acid must, however, not be present. 4. Marsh’s Test.*—Apply this test as described for arsenic. On the introduction of the antimony solution to the apparatus, anti- moniuretted hydrogen is produced, and the flame becomes bluish- green in colour. A black stain is produced by this flame on cold porcelain, just as in the case of arsenic ; but the stain is less lustrous, and is insoluble in sodium hypochlorite, NaOCl. 4 SbH3 + 3 02 = 4 Sb + 6 H30. 5. Hoffmann’s Test.*—Apply this test as for arsenic. A black precipitate is obtained in the solution of silver nitrate: this con¬ tains antimony as SbAg3, whilst nitric acid remains in solution. SbH3 + 3 AgN03 = SbAg3 + 3 HN03. * The objection to these tests referred to under Arsenic applies here as well of course.