Ammoniacal silver nitrate solution

Treat with ammoniacal silver nitrate solution and warm. 

It must be noted, however, that nitroso, azoxy and azo compounds when subjected to the same treatment yield res])ectively hydroxylamines, hydrazo and hydrazine compounds, all of which reduce ammoniacal silver nitrate solution in the cold. 

Aromatic aldehydes react with the dimedone reagent (Section 111,70,2). All aromatic aldehydes (i) reduce ammoniacal silver nitrate solution and (ii) restore the colour of SchifiF s reagent many react with sodium bisulphite solution. They do not, in general, reduce Fehling s solution or Benedict s solution. Unlike aliphatic aldehydes, they usually undergo the Cannizzaro reaction (see Section IV,123) under the influence of sodium hydroxide solution. For full experimental details of the above tests, see under Ali-phalic Aldehydes, Section 111,70. They are easily oxidised by dilute alkaline permanganate solution at the ordinary temperature after removal of the manganese dioxide by sulphur dioxide or by sodium bisulphite, the acid can be obtained by acidification of the solution. 

The free selenazole hydrazines are solids, sometimes well crystallized compounds. They show the typical properties of hydrazines. Thus they reduce Fehling s solution on warming and liberate silver, even in the cold, from ammoniacal silver nitrate solution. Further, they react with carbonyl compounds for example, benzylidene hydrazones are formed with benzaldehyde. These are identical with the hydrazones formed by direct condensation from benzaldehyde selenosemicarbazone and the corresponding a-halogenocarbonyl compound. 2-Hydrazino-4-phenylselenazole has also been reacted with acetophenone. The 2-a-methylbenzylidenehydrazone of 4-phenyl-selenazole (2, K = CJl, R" = H, R" = NH—N CMe-aH ) forms golden yellow plates mp 171°C. ... 

If a group-specific reagent is now used, e.g. one that is chosen to react specifically with the reducing properties of aldehydes (ammoniacal silver nitrate solution) or to react with ketones (2,4-dinitrophenylhydrazine [9]) it is very simple to determine which form of alcohol is present in the sample. 

Reagent 2 Spray solution 2 Ammoniacal silver nitrate solution (precise composi-... 

Soliman and Belal investigated argentimetric (67,68) and mercurimetric (69) methods. Hydralazine precipitates silver from ammoniacal silver nitrate solution. The silver is dissolved with hot nitric acid and titrated with ammonium thiocyanate solution. Alternatively, mercury is precipitated from alkaline potassium mercuric iodide solution. The precipitated mercury is dissolved by adding excess standard iodine solution. The excess iodine is back-titrated with sodium thiosulfate solution after acidifying with acetic acid. 

Experiment.—Test the reducing effect of phenylhydroxylamine by dissolving material on the point of a knife in 2 c.c. of warm water and adding to the solution a few drops of ammoniacal silver nitrate solution. 

Silver solutions used in photography can become explosive under a variety of conditions. Ammoniacal silver nitrate solutions, on storage, heating or evaporation eventually deposit silver nitride ( fulminating silver ). Silver nitrate and ethanol may give silver fulminate, and in contact with azides or hydrazine, silver azide. These are all dangerously sensitive explosives and detonators [1], Addition of ammonia solution to silver containing solutions does not directly produce explosive precipitates, but these are formed at pH values above 12.9, produced by addition of alkali, or by dissolution of silver oxide in ammonia [2]. 

Aldehydes. — On heating 10 cc. of acetone with 5 cc. of ammoniacal silver nitrate solution for fifteen minutes on a steam-bath, the mixture must not acquire a brown color. 

Substances which Reduce Ammoniacal Silver Nitrate Solution. — On heating a mixture of 1 cc. of glycerin and 1 cc. of ammonia water on the water-bath to 60° C., and then immediately adding 3 drops of silver nitrate solution, neither... 

Add a few drops to 10 c.cs. ammoniacal silver nitrate solution and warm in a bath of hot water. Silver mirror formed. 

By treating the spot with hot nitric acid, evaporating to dryness on a water-bath, dissolving the residue in two drops of water and adding ammoniacal silver nitrate solution (2 or 3 drops) in presence of arsenic a brick-red precipitate of silver arsenate is formed. 

Ammoniacal silver nitrate solution (Totten s solution). Aldehydes alone reduce Tollen s reagent and produce a silver mirror on the inside of the test tube. Add 2-3 drops (or 0.05 g) of the compound to 2-3 ml of Tollen s solution contained in a clean test tube (the latter is preferably cleaned with hot nitric acid). If no reaction appears to take place in the cold, warm in a beaker of hot water. (CAUTION After the test, pour the contents of the test tube into the sink and wash the test tube with dilute nitric acid. Any silver fulminate present, which is highly explosive when dry, will thus be destroyed.)... 

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