Notes on analytical chemistry : for students in medicine / by Albert J. Bernays.
- Albert Bernays
- Date:
- 1886
Licence: Public Domain Mark
Credit: Notes on analytical chemistry : for students in medicine / by Albert J. Bernays. Source: Wellcome Collection.
42/160 page 32
![+ CO2 + H2O. Such water is also softened by adding sufficiency of calcium hydroxide : CaC03,H,C03 + CaH^O^ = 2 CaCOs + 2K,0.'] KOH, white CaH.Pa, insoluble. NH4OH, no reaction. CaS04, of course no reaction. Distinction between Ba, Sr, and Ca : Ba immediately precipitated, Sr on heating, Ca not at all. Concentrated solutions of sulphates precipitate the chloride, nitrate, &c. Ammonium oxalate, (NHJ2C2O4, precipitates white calcium oxalate, insoluble in acetic acid. This test is decisive if calcium sulphate has given no precipitate. Soluble salts, a yellowish-red color to flame. 28. Magnesium, Mg = 24. Silvery lustrous metal. Sp. gr. 1'74. Melts at a red heat. By the action of sodium upon the chloride by heat: MgClj + Na^ = 2NaCH-Mg. Dissolves in the three dilute common acids with evolution of hydrogen ; not in KOH. Burns brilliantly to magnesimn oxide, or magnesia, MgO. Magnesium oxide, MgO, the only base of magnesium. White, amorphous powder; when moistened, blues red litmus, but requires 5142 parts of cold water for solution. Practically insoluble in water, and precipitated by lime- water from its soluble salts. Chief soluble salts: MgS0^,7HjO is Epsom salts; MgClj.eH^O: Mg2N03,6H20. Tests for magnesium in soluble salts. V. NH^Ol + (NHJaCOg, no precipitate. But, if ammonium chloride has been forgotten, a precipitate, increasing, of basic magnesium carbonate. No precipitate in presence of free acids, as then an ammonium salt is formed with the ammonium of the carbonate. KOH, white MgH202, insoluble. NH4OH, white MgHaOj; increased by heat. No precipitate in presence of free acids. NaHCOs, a precipitate on heating. Therefore a Mg salt a test for a bi-carbonate of sodium or potassium. Na2HP04, a white precipitate of MgHPO^, greatly increased by NH.OH. Ammonium chloride, then NH4OH, and then NaaHPO^, a white crystalline precipitate of MgNH4P04,6H20. Magnesium is precipitated as MgNH^POi.G HgO, after the sepa- ration of calcium by ammonium oxalate. No color to flame; MgO, rose-colored, when ignited on platinum with cobalt nitrate. Group F7.—Metals of the alkalies. The carbonates are all soluble in water: (lithium carbonate, however, with difficulty soluble, and may be precipitated by sodium carbonate). From any salt of ammonium, in which the latter is not at once recognisable by the smell, the carbonate of sodium test, on boiling, liberates](https://iiif.wellcomecollection.org/image/b21499056_0042.jp2/full/800%2C/0/default.jpg)
