Chemical elements
    Amorphous Sulphur
    Colloidal Sulphur
    Physical Properties
    Chemical Properties
      Hydrogen Sulphide
      Metal Polysulphides
      Hydrogen Polysulphides
      Hydrogen Pentasulphide
      Hydrogen Trisulphide
      Hydrogen Disulphide
      Sulphur Monofluoride
      Sulphur Tetrafluoride
      Sulphur Hexafluoride
      Sulphur Monochloride
      Sulphur Dichloride
      Sulphur Tetrachloride
      Sulphur Monobromide
      Thionyl Fluoride
      Sulphuryl Fluoride
      Fluorosulphonic Acid
      Thionyl Chloride
      Sulphuryl Chloride
      Sulphur Oxytetrachloride
      Pyrosulphuryl Chloride
      Chlorosulphonic Acid
      Thionyl Bromide
      Sodium Sulphoxylate
      Sulphur Dioxide
      Sulphurous Acid
      Sulphur Trioxide
      Pyrosulphuric Acid
      Sulphuric Acid
      Persulphuric Anhydride
      Persulphuric Acid or Perdisulphuric Acid
      Permonosulphuric Acid
      Amidopermonosulphuric Acid
      Thiosulphuric Acid
      Polythionic Acids
      Dithionic Acid
      Trithionic Acid
      Tetrathionic Acid
      Pentathionic Acid
      Wackenroders Solution
      Hexathionic Acid
      Polythionic Acids
      Sulphur Sesquioxide
      Hydrosulphurous Acid
      Nitrogen Sulphide
      Nitrogen Persulphide
      Nitrogen Pentasulphide
      Nitrogen Chlorosulphide
      Trithiazyl Chloride
      Thiotrithiazyl Chloride
      Dithiotetrathiazyl Chloride
      Nitrogen Bromosulphide
      Thiotrithiazyl Bromide
      Thiotrithiazyl Iodide
      Thiotrithiazyl Nitrate
      Thiotrithiazyl Hydrogen Sulphate
      Thiotrithiazyl Thiocyanate
      Sulphonic Acids
      Amidosulphonic Acid
      Imidosulphonic Acid
      Nitrilosulphonic Acid
      Hydroxylamine-monosulphonic Acid
      Nitrososulphonic Acid
      Hydroxylamine-disulphonic Acid
      Hydroxylamine-isodisulphonic Acid
      Hydroxylamine-trisulphonic Acid
      Dihydroxylamidosulphonic Acid
      Sulphazinic Acid
      Sulphazotinic Acid
      Dehydrosulphazotinic Acid
      Nitrosulphonic Acid
      Nitrosulphonyl Chloride
      Nitrosulphonic Anhydride
      Nitrosulphuric Acid
      Nitrosodisulphonic Acid
      Sulphonitronic Acid
      Sulphates of Hydroxylamine
      Hydroxylamine Dithionate
      Hydrazine Dithionate
      Hydrazine Amidosulphonate
      Carbon Subsulphide
      Carbon Monosulphide
      Carbon Disulphide
      Thiocarbonic Acid
      Ammonium thiocarbonate
      Thiolcarbonic Acid
      Xanthic Acid
      Perthiocarbonic Acid
      Sodium perthiocarbonate
      Carbonyl Sulphide
      Thiocarbonyl Chloride
      Thiocarbonyl Tetrachloride or
      Carbon Hexachlorosulphide
      Trichloromethyl Disulphide
      Thiocarbonyl Sulphochloride
      Carbon Bromosulphide
      Amino-derivatives of Thiocarbonic Acid
      Dithiocarbamic Acid
      Azidodithiocarbonic Acid
      Cyanogen Monosulphide
      Cyanogen Trisulphide
      Sulphur Thiocyanate
      Disulphur Dithiocyanate
      Thiocyanic Acid
      Dithiocyanic Acid
      Trithiocyanuric Acid
      Perthiocyanic Acid

Nitrogen Pentasulphide, N2S5

Nitrogen Pentasulphide, N2S5, is formed by the decomposition of the yellow sulphide, N4S4, and its derivatives. It is formed, for example, when the yellow sulphide is exploded by friction, when the compounds of N4S4 with the halogens or with nitrous or nitric acid are boiled with water, and also when N4S4 is heated carefully with lead oxide.

The pentasulphide may be prepared by heating together yellow nitrogen sulphide and carbon disulphide under pressure:

N4S4 + 2CS2 = N2S5 + S + 2CNS.

A deep red solution is obtained and a brown precipitate. The solution consists of nitrogen pentasulphide and sulphur in carbon disulphide, the pentasulphide being extracted by means of ether. If the product is pure, containing no sulphur, it crystallises from the ether solution in tablets of metallic appearance somewhat resembling iodine. The brown precipitate has the composition C3N3S3.

Nitrogen pentasulphide may also be obtained by the action of carbon tetrachloride on N4S4 at 125° C. In this case a black complex by-product is obtained.

The action of zinc dust on a suspension of thiotrithiazyl chloride, N3S4Cl, also gives the pentasulphide.

Nitrogen pentasulphide is a deep red liquid, which solidifies to a crystalline mass strongly resembling iodine. It melts at 10° to 11° C. Its specific gravity at 18° C. is 1.901. It is insoluble in water but soluble in most organic solvents. It is unstable in solution, especially on exposure to light, the products of its decomposition being N4S4 and sulphur. When boiled with water or with aqueous solutions of the caustic alkalis, ammonia and sulphur are formed. An alcoholic solution of an alkali hydroxide added to an alcoholic solution of nitrogen pentasulphide produces a transient but intense violet-red coloration. So characteristic is this reaction that it may be used for the detection of very small quantities of the pentasulphide. Alcoholic solutions of the alkali sulphides yield ammonia and a polysulphide. With hydrogen sulphide, ammonium polysulphide and sulphur are formed, thus:

N2S5 + 4H2S = (NH4)2S5 + 4S.

The pentasulphide is violently oxidised by concentrated nitric acid, with formation of sulphuric acid, whilst dilute hydrochloric or sulphuric acid yields the ammonium salt and sulphur.

Cryoscopic determinations of the molecular weight, using benzene as solvent, give results agreeing with the formula N2S5.

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