Chemical elements
    Physical Properties
    Chemical Properties
      Iridium Monochloride
      Iridium Dichloride
      Iridium Trichloride
      Potassium Chloriridite
      Sodium Chloriridite
      Ammonium Chloriridite
      Aquo Chloriridites
      Iridium Tetrachloride
      Potassium Chloriridate
      Sodium Chloriridate
      Ammonium Chloriridate
      Silver Chloriridate
      Thallium Chloriridate
      Iridium Tribromide
      Iridium Tetrabromide
      Potassium Bromiridate
      Sodium Bromiridate
      Ammonium Bromiridate
      Iridium Oxybromide
      Iridium Tri-iodide
      Potassium Iodiridite
      Iridium Tetra-iodide
      Potassium Iodiridate
      Iridium Monoxide
      Iridium Sesquioxide
      Iridium Dioxide
      Iridium Trioxide
      Iridium Monosulphide
      Iridium Sesquisulphide
      Iridium Disulphide
      Iridium Sesquisulphite
      Potassium Iridium Sulphite
      Iridium Sesquisulphate
      Potassium Iridium Alum
      Ammonium Iridium Alum
      Caesium Iridium Alum
      Rubidium Iridium Alum
      Iridium Disulphate
      Iridium Sesquiselenide
      Hydrogen Iridi-nitrite
      Potassium Iridi-nitrite
      Sodium Iridi-nitrite
      Ammonium Iridi-nitrite
      Hydrogen Iridicyanide
      Potassium Iridicyanide
      Barium Iridicyanide
    PDB 1c1k-4enb

Potassium Iridi-nitrite, K3Ir(NO2)6

Potassium Iridi-nitrite, K3Ir(NO2)6, which is conveniently prepared by adding sodium nitrite to a hot acidulated solution of sodium chlor-iridite until it is bleached. The solution is boiled to expel nitrous oxides, and potassium chloride is added in excess, whereupon iridium potassium nitrite is precipitated as a white mass.

It is also formed by adding potassium nitrite to a solution of iridium sulphate in the warm. It is a white powder, which readily dissolves in boiling water, but which is insoluble in potassium chloride solution.

At 300° C. it begins to decompose, whilst at 440° C. decomposition is rapid. Heated in vacuo at this latter temperature, nitrogen and nitric oxide are liberated, a greenish black powder remaining behind. This, on treatment with water, leaves after a time a heavy black powder consisting of 6IrO2.K2O, which, it is suggested is probably the salt of the hypothetical hexiridous acid, (IrO)6O5(OH)2 or 6IrO(OH)2 - 5H2O. When the double nitrite is heated to redness in a muffle, the residue on thorough washing has the composition 12IrO2.K2O, which Joly and Leidie suggest may be the potassium salt of the hypothetical dodeca-iridous acid, (IrO)2O11(OH)2 or 12IrO(OH)2 - 11H2O. It is very doubtful, however, if we are justified in assuming that these are separate chemical entities.

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