A system of instruction in qualitative chemical analysis / by Dr. C. Remigius Fresenius .. ; edited by J. Lloyd Bullock, F.C.S.
- Carl Remigius Fresenius
- Date:
- 1855
Licence: Public Domain Mark
Credit: A system of instruction in qualitative chemical analysis / by Dr. C. Remigius Fresenius .. ; edited by J. Lloyd Bullock, F.C.S. Source: Wellcome Collection.
91/342 page 65
![SODA. G5 § 8/.] with a small quantity of water, alcohol added, and the latter heated and then ignited, the flame appears violet. The presence of soda obscures this reaction also. § 87. b. Soda (Na O). 1. Soda, its hydrate, and salts present in general the same deport- ment and properties as potassa and its corresponding compounds. The oily fluid which soda forms by deliquescing in the air, resolidifies speedily by absorption of carbonic acid. Carbonate of soda crystallizes readily, and effloresces rapidly when exposed to the air. The same applies to sulphate of soda. 2. Antbnoniate of potassa produces in neutral or alkaline solutions of salts of soda a white crystalline precipitate of antimoniate of soda (Na O, Sb 05). In concentrated solutions, this precipitate is formed im- mediately ; but from dilute solutions it separates only after the lapse of some time. Vigorous shaking of the mixture promotes the formation of the precipitate. If the fluid, after the addition of the reagent, be stirred with a glass rod, moving the latter along the sides of the vessel, the lines de~ scribed will, even in very dilute solutions, speedily becomes visible, since the precipitate forms first on the parts touched by the rod. The presence of neutral salts of potassa does not interfere with the formation of the pre- cipitate. Carbonate of potassa, however, prevents its separation wholly or partially, according to the greater or less proportion in which it is present. In cases therefore where the solution under examination contains this salt, it is necessary to precede the application of the antimoniate of potassa by addition of hydrochloric or acetic acid until the reaction of the solution remains only feebly alkaline. Acid solutions must first be neutralized with potassa, since otherwise the reagent would suffer decomposition, and hydrated antimonic acid or acid antimoniate of potassa be precipitated from it. 3. Salts of soda (more particularly chloride of sodium) when exposed on a platinum wire to the inner blowpipe flame, color the outer flame intensely yellow, owing to reduction of the soda and subsequent re- oxidation of the reduced sodium. This reaction remains clearly per- ceptible, even if the soda contains a considerable admixture of potassa. 4. If a salt of soda (more particularly chloride of sodium) is heated with a small quantity of water, alcohol added, and the latter heated and then ignited, the flame appears strongly yellow. The presence of a salt of potassa does not impair the distinctness of this reaction. 5. Bichloride of platinum produces no precipitate in solutions of salts of soda ; tartaric acid only when a highly concentrated solution of soda or carbonate of soda is mixed with a saturated solution of tartaric acid in F](https://iiif.wellcomecollection.org/image/b28080361_0091.jp2/full/800%2C/0/default.jpg)
