Course of practical chemistry : as adopted at University College, Toronto / by Henry Croft.

  • Croft, Henry.
Date:
1860
Catalogue details

Licence: Public Domain Mark

Credit: Course of practical chemistry : as adopted at University College, Toronto / by Henry Croft. Source: Wellcome Collection.

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    water poured on. After standing some time, being frequently stirred, the solution is filtered. The first portions of water used often con- tain alkali. CHLOEIDE OF CALCirM. Marble or chalk is dissolved in hydrochloric acid, filtered, the solution supersaturated with ammonia, again filtered from the pre- cipitate, the filtrate boiled and precipitated with solution of carbonate of ammonia, and the precipitate well washed. This is perfectly pure carbonate of lime, and is used in mineral analyses where the alkali is to be determined. This pure carbonate is then introduced into heated dilute hydrochloric acid, until neutralized, and the solu- tion filtered. The chloride must be neutral and free from iron and ammonia. The former is detected by sulphide of ammonium, the latter by boil- ing with excess of caustic potassa. SULPHATE OF LIME. Pure chloride of calcium is precipitated with sulphuric acid, the precipitate well washed out until the filtrate is no longer acid, the residue on the filter boiled with a large ^quantity of water, and the solution filtered. OnLORIDB OF MAGNESIUM. May be obtained like the foregoing salt, using the commercial carbonate; it may however be conveniently replaced by the sulphate of magnesia, which, as sold by the druggists, is sufl&ciently pure for analytical purposes. SESQUICHLOllIDE OF IRON. Tinctura ferri muriatid will answer for most purposes. The pure salt is obtained by dissolving hydrated sesquioxide of iron in heated dilute hydrochloric acid to saturation, and filtering. The hydrated oxide of iron is obtained by dissolving green vitriol (ante p. 14) in water, boiling, adding nitric acid as long as efi'erves- cence is produced, precipitating with ammonia, filtering and washing. PROTOCHLORTDE OF TIN. Digest excess of granulated tin with strong hydrochloric acid, dilute with water and filter into a bottle containing some pieces of