Acetate

(Chem.) Salt formed by the union of a base with acetic acid. Many of the acetates are of great importance in the arts, principally the following. Acetate of Alumina , extensively manufactured for the use of the dyer and calico-printer. The common red mordant is prepared by precipitating 100 parts alum in solution or sulphate of alumina by means of 120 of crystallized acetate of lead: the sulphate of potash of the alum remains undecomposed in the solution. When the liquor is used as a mordant, it is thickened with gum and applied by means of blocks to the cloth. Many other acetates are also used in calico-printing; for example, that of Manganese, Zinc, and Iron. Acetate of Ammonia, a very soluble salt, frequently used medicinally as a diaphoretic. Acetate of Barium is more soluble in cold than in hot water, and slightly soluble in alcohol. It is occasionally used as a precipitant for sulphuric acid; when distilled it furnishes acetone. Acetate of Copper. See VERDITER, and VERDIGRIS. Acetate of Lead. See SUGAR OF LEAD, and GOULARD'S EXTRACT. Acetate of Lime crystallizes in silky, anhydrous needles, which are very soluble in water: if heated to 248° it becomes strongly phosphorescent by gentle friction. Acetate of Potash , employed medicinally as a diuretic, is an anhydrous, foliated, very deliquescent, fusible salt, abundantly soluble in alcohol. Acetate of Silver , occasionally employed as a reagent, is readily obtained by mixing a concentrated solution of nitrate of silver with a solution of acetate of potash, or acetate of soda. It is sparingly soluble in cold water, but readily di olved by hot water, which on cooling deposits it in thin, flexible, silky needles. Acetate of Sodium crystallizes in oblique monoclinic prisms: it fuses readily. This salt is prepared in large quantities during the purification of wood-vinegar. The acetates are distinguished by the pungent odor of acetic acid which they emit when heated with sulphuric acid.