Licence: Public Domain Mark
Credit: Qualitative chemical analysis / by C. Remigius Fresenius. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![§ 97.] is aUowed to spirt up in the flame. In presence of baryta, the strontia reaction is seen only when the sample moistened with hydrochloric acid is fii'st introduced into the flame. The strontia spectrum is shown in the coloured plate. It contains a number of characteristic lines, more especially the orange line a, the red lines ^ and y, and the blue line 5 ; the latter is more particularly suited for the detection of strontia in presence of baryta and Hme. i 9 Sulphate of strontia is completely decomposed by continued diges- tion with solutions of carbonate of ammonia, or of the carbonates or bicarbonates of tbe alkaUes, but much more rapidly by boihng with a solution of 1 part of carbonate of potassa and 3 parts of sulphate of potassa (essential difference between sulphate ot strontia and sulphate of baryta). §97. c. Lime, CaO [CaO]. 1. Lime, its hydrate and its salts, in their general properties and reactions, bear a very close resemblance to baryta and strontia and their corresponding compounds. Hydrate of lime is far more sparingly soluble in water than the hydi^ates of baryta and strontia; it is also less soluble in hot than in cold water. Hydrate of lime loses its water on ignition. Chloride of calcium and nitrate of lime are soluble in absolute alcohol, and deHquesce when exposed to the air. 2. Ammonia, potassa, soda, carbonates of tlie alkalies, and phosphate of soda give nearly the same reactions with salts of lime as with salts of baryta. Kecently precipitated carbonate of lime, CaOjOOj [CaCOj], is bulky and amorphous, but after a time, and imme- diately when heated in the liquid, it falls down and assumes a crystal- line form. Eecently precipitated carbonate of lime dissolves pretty readily in solution of chloride of ammonium; but the solution speedily becomes turbid, and deposits the greater part of the dissolved salt in the form of crystals. 3. Sulphuric acid and sulphate of soda, in highly concentrated solutions of lime salts, immediately produce a white precipitate of sulphate of lime, CaO,S03 + 2aq [OaSO„2H,0], which redissolyes com- pletely in a large proportion of water, and is far more soluble in acids. Sulphate of lime dissolves readily when boiled with a concentrated solution of sulphate of ammonia. In less concentrated solutions of lime, the precipitates are formed only after the lapse of some time; and no precipitation whatever takes place in dilute solutions. Solution of sulphate of lime of course cannot produce a precipitate in salts of lime; but even a cold saturated solution of sulphate of potassa, mixed with 3 parts of water, does not produce a precipitate until the mixture has been allowed to stand from twelve to twenty-four hours. If two volumes of alcohol are added to solutions of lime which are so very dilute that sulphuric acid has no apparent action on them, a precipitate will form either immediately, or after the lapse of some time. 4. Hydrofluosilicic acid does not precipitate salts of lime, even when an equal volume of alcohol is added, 5. Oxalate of ammonia produces a white pulverulent precipitate of oxalate of lime. If the solutions are moderately concentrated or hot, the precipitate, 2CaO,C^05 + ^'^^ [CaCo04,H.p]j forms at once ; but](https://iiif.wellcomecollection.org/image/b21966953_0121.jp2/full/800%2C/0/default.jpg)
