446 PRACTICAL ORGANIC CHEMISTRY ammonia is driven off. The solution of the pure ammonium salt is now cooled and treated with a small excess of silver nitrate solution, when the silver salt of the acid is precipitated. Dissolve 1-5 ml. of glacial acetic acid in about 50 ml. of distilled water and then* add dilute ammonia solution until the well-stirred mixture smells of ammonia. Boil the solution gently until no odour of ammonia can be detected in the steam and until a red litmus-paper placed in the steam gives no blue coloration. Then cool and add dilute (e.g., 10%) silver nitrate solution with stirring until no further precipita-tion of the white silver acetate occurs. Filter through a small Buchner funnel, drain well and then wash at least three times with small quanti-ties of water to remove excess of silver nitrate. Then drain thoroughly, transfer to a small evaporating-basin, cover with a watch-glass and dry either in a steam oven or in a vacuum desiccator. Powder the cold
This is the end of the preview. Sign up
access the rest of the document.