Silver nitride

To minimize the formation of fuhninating silver, these complexes should not be prepared from strongly basic suspensions of silver oxide. Highly explosive fuhninating silver, beheved to consist of either silver nitride or silver imide, may detonate spontaneously when silver oxide is heated with ammonia or when alkaline solutions of a silver—amine complex are stored. Addition of appropriate amounts of HCl to a solution of fuhninating silver renders it harmless. Stable silver complexes are also formed from many ahphatic and aromatic amines, eg, ethylamine, aniline, and pyridine. 

Silver Nitride. (Fulminating Silver). Ag3N, mw 337.65, N4.15%, blk-grey powd, mp 25° (start of decompn), d 9.0 lg/cc at 19°. Sol in weak acids, si sol in aq ammonia sol in aq solns of Na chioride and K cyanide. Prepd by treating aq Ag oxide with aq ammonia soln, or by heating coned ammoniacal Ag chloride with solid KOH until evolution of ammonia ceases. The thoroug-ly washed product must be stored under w and, even so, is sensitive to touch (Refs 1—7)... 

Exposure of ammoniacal silver chloride solutions to air or heat produces a black crystalline deposit of fulminating silver , mainly silver nitride, with silver diimide and silver amide also possibly present [1], Attention is drawn [2] to the possible explosion hazard in a method of recovering silver from the chloride by passing an ammoniacal solution of the chloride through an ion exchange column to separate the Ag(NH3)+ ion, prior to elution as the nitrate [3], It is essential to avoid letting the ammoniacal solution stand for several hours, either alone or on the column [2], See Silver nitride... 

A silvering solution exploded when disturbed. This is a particularly dangerous mixture, because both silver nitride and silver fulminate could be formed. 

During preparation of an oxidising agent on a larger scale than described [1], addition of warm sodium hydroxide solution to warm ammoniacal silver nitrate with stirring caused immediate precipitation of black silver nitride which exploded [2], Similar incidents had been reported previously [3], including one where explosion appeared to be initiated by addition of Devarda s alloy (Al—Cu—Zn) [4], The explosive species separates at pH values above 12.9, only produced when alkali is added to ammoniacal silver solutions, or when silver oxide is dissolved with ammonia [5], The Sommer Market reagent mixture used to identify cellulose derivatives led to a severe explosion [6],... 

See Silver nitride, also Ammonia Silver compounds See also silvering solutions, tollens reagent... 

Silver oxide and ammonia or hydrazine slowly form explosive silver nitride and, in presence of alcohol, silver fulminate may also be produced. 

See other peroxoacid salts, silver compounds 0038. Silver nitride... 

For analysis, a silver-containing solution was made alkaline with 25% sodium hydroxide solution and filtered, then the precipitate was washed with ammonium hydroxide to redissolve the silver. Hydrazine (as sulfate) was added to precipitate the silver, and when the mixture was heated, an explosion occurred. This could have been caused by precipitation of explosive silver nitride, rapid catalytic decomposition by silver compounds of the hydrazine salt, and/or ignition of the hydrogen evolved. 

Oxygen (Gas), Carbon disulfide, Mercury, Anthracene, 4831 Oxygen (Liquid), Carbon, Iron(II) oxide, 4832 Oxygen difluoride, Hexafluoropropene, Oxygen, 4317 Potassium chlorate, Manganese dioxide, 4017 f Propionyl chloride, Diisopropyl ether, 1163 f Propylene oxide, Sodium hydroxide, 1225 Silver azide, 0023 Silver nitride, 0038 Sodium carbonate, 0552 Sodium peroxoborate, 0155 Tetrafluoroammonium tetrafluoroborate, 0133 Triallyl phosphate, 3184... 

Silver 5-aminotetrazolide, 0392 Silver hexanitrodiphenylamide, 3429 Silver imide, 0030 Silver nitride, 0038 Silver iV-nitrosulfuric diamidate, 0016 Silver /V-pcrchlorylbcnzylamidc. 2734 Silver tetrazolide, 0366... 

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]. 

A simple and economical method for recovering silver residues by dissolution in used photographic fixer (thiosulfate) solution, then precipitation by addition of zinc powder, is detailed [1]. After the acid digestion phase of silver recovery operations, addition of ammonia followed immediately by addition of ascorbic acid as reducant gives a near-quantitative recovery of silver metal, and avoids the possibility of formation of silver nitride [2],... 

A silver-containing solution was basified with sodium hydroxide, and after filtration, ammonia solution was used to wash residual silver from the filter. Hydrazine sulfate was then added to precipitate metallic silver and when the mixture was heated it exploded. This may have been caused by formation of silver nitride and/or hydrazine-silver complexes, both of which are explosively unstable. 

Silver nitride (Ag N) Sensitive to shock, underwater explosive upon contact with water. 

Several silver compounds are extremely explosive—for example, silver picrate, silver nitride, silver peroxide, silver perchlorate, and silver permanganate. They are used in various types of explosives and as concussion caps for rifle and pistol ammunition. 

Shellac Silver azide Silver fulminate Silver NENA Silver nitride SNF... 

Figure A. 150 Silver nitride primary high explosive.

Whitman s rept described several cases where laboratory prepn of ammoniacal Ag salt solns led to explns. In addn, quotations from the literature sources demonstrate the variety of warnings (or lack of the same) that have been given for Ag salt-ammonia systems. The majority of workers discussed in this rept appear to favor the theory that Ag3 N (silver nitride or fulminating silver ) i s the explosive species involved. Precipitation of a dark material prior to expln was reptd in several of the cases cited by the author Preventive measures and a list of literature references are included in the report For addnl info on Fulminating Silver, see Vol 6 of this Encycl... 

Alkaline Earths Chlorides. lit) ee.. of the 1 20 aqueous solid ion should he nlTcofcd neither by ammonium oxalate Solid inn nor hy silver nitride solution. 

J. Berchtold, Behavior of Silver Nitride Towards the Effects of High Intensities of Light, and Their Use for Producing Images , IntemConfPhot, London (1953) 35) F.P. 

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