AC′ETATE

(ăs′-). Syn. Ace′tas , L.; Acetate , Fr.; E igsäure salze , Ger. In chemistry , a salt consisting of C 2 H 3 O 2 (sometimes called the acid-radical of the acetates) with hydrogen, a metal, or a compound basic radical; e.g. , | Hydrogen acetate (acetic acid) | HC2H3O2 | | Pota ium acetate | KC2H3O2 | | Lead (plumbic) acetate | Pb(C2H3O2)2 | | Ammonium acetate | NH4C2H3O2 | Salts of acetic acid (HC 2 H 3 O 2 ) with the alkaloids are likewise termed acetates; e.g. , Morphia acetate. C 17 H 19 NO 3 . C 2 H 4 O 2 Prep. That of the commercial acetates, and of many others, is noticed under the respective metals. In general, they may all be formed by direct solution of the carbonate, hydrate or oxide of the metal whose acetate it is desired to form, in dilute acetic acid; or from a solution of an acetate and of another salt of the metal, by double decomposition. In either case, the resulting solution must be carefully evaporated by a gentle heat, and, where po ible, crystallised. Prop., . All the neutral acetates, except those of molybdenum and tungsten, are more or le soluble in water, several so much so as to be uncrystallizable; many di olve in alcohol; they suffer decomposition at a dull red heat, and by distillation, at that temperature, yield acetone and water, or acetone and acetic acid, and leave a carbonaceous residuum; at a full red-heat, those of pota ium, sodium, barium, strontium, calcium, and magnesium, are converted into carbonates, whilst the other metallic acetates leave behind the pure metal, or its oxide. The aqueous solutions of the alkaline acetates soon turn mouldy and suffer decomposition. No more of them should, therefore, be di olved at once than is required for immediate use. Char., tests, . The acetates are known—1. By evolving fumes of acetic acid, recognisable by its peculiar and characteristic odour, on the addition of strong sulphuric acid:—2. By evolving the vapour of acetic ether (known by its peculiar and agreeable odour) when heated with a mixture of about equal parts of concentrated sulphuric acid and alcohol.