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.
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![§§ 18, 19.] ETHER. HYDROCHLORIC ACID. Zl Uses.—Many substances are soluble in alcohol, whilst others are inso- luble in this menstruum. Alcohol is therefore frequently employed to effect the separation of the former from the latter; for instance, to separate chloride of strontium from chloride of barium. Alcohol serves likewise to precipitate from aqueous solutions such substances as are insoluble in it, e. g. malate of lime. We use alcohol moreover for the production of various kinds of ether (especially of acetic ether, which is particularly characterized by its agreeable odor) ; and likewise to co- operate with acids in the reduction of certain substances, for instance, of binoxide of lead, chromic acid, &c. Alcohol serves also for the detec- tion of various substances which impart a characteristic tint to its flame ; such are especially boracic acid, strontia, soda, and potassa. § 18. 3. Ether (C4 H5 O = Ae O). Ether finds but very limited application in the analysis of inorganic bodies. It serves indeed almost exclusisely to detect and isolate bromine (§ 44) ; and for this purpose the officinal ether of commerce is sufficiently pure and strong. b. Reagents which are principally used as chemical solvents. § 19. 1. Hydrochloric acid (H Cl). Preparation.—Pour a cooled mixture of seven parts of concentrated sul- phuric acid and two parts of water, over four parts of chloride of sodium in a retort; expose the retort, with slightly raised neck, to the heat of a sand- bath, until the evolution of gas ceases ; conduct the evolved gas, by means of a double-limbed tube, into a flask containing 6 parts of water, and take care to keep this receiver constantly cool. To prevent the gas from receding, the tube ought only to dip about one line into the water of the receiver. Should the sulphuric acid employed in the process contain nitric acid, the gas which passes over first (and which in that case contains chlorine), must be received separately. The hydrochloric acid produced is diluted with water until its specific gravity is from I'll to 1*12. Tests.—Hydrochloric acid intended for the purposes of chemical analysis must be perfectly colorless, and leave no residue upon evapora- tion ; it should not discolor indigo-solution upon ebullition. Chloride of , barium ought not to produce any precipitate, either in the highly diluted . acid (sulphuric acid), nor even after ebullition with nitric acid (sulphurous acid). Hydrosulphuric acid must leave it unaltered. Sulphocyanide of potassium must not impart the least red tint to the diluted acid. rjjl ^ ^ Uses.—Hydrochloric acid serves as a solvent for a great many sub-](https://iiif.wellcomecollection.org/image/b28080361_0047.jp2/full/800%2C/0/default.jpg)
