Chemical elements
  Arsenic
      Occurrence
      Ubiquity
      History
    Isotopes
    Energy
    Production
    Application
    Physical Properties
    Chemical Properties
      Aluminium Arsenide
      Antimony Arsenides
      Barium Arsenide
      Bismuth Arsenides
      Cadmium Arsenides
      Calcium Arsenide
      Cerium Arsenide
      Chromium Arsenides
      Cobalt Arsenides
      Copper Arsenides
      Gold Arsenides
      Iridium Arsenide
      Iron Arsenides
      Lead Arsenides
      Lithium Arsenide
      Magnesium Arsenide
      Manganese Arsenides
      Mercury Arsenides
      Molybdenum Arsenide
      Nickel Arsenides
      Niobium Arsenide
      Palladium Di-arsenide
      Platinum Arsenides
      Potassium Arsenides
      Rhodium Arsenide
      Ruthenium Arsenide
      Silver Arsenides
      Sodium Arsenide
      Strontium Arsenide
      Thallium Arsenide
      Tin Arsenides
      Tungsten Arsenide
      Uranium Arsenide
      Zinc Arsenides
      Arsenic Subhydride
      Arsenic Monohydride
      Arsenic Trihydride
      Arsenic Trifluoride
      Arsenic Pentafluoride
      Arsenic Nitrosyl Hexafluoride
      Arsenic Trichloride
      Arsenic Oxychloride
      Arsenic Pentachloride
      Arsenic Tribromide
      Arsenic Oxybromide
      Arsenic Moniodide
      Arsenic Diiodide
      Arsenic Triiodide
      Arsenic Pentiodide
      Arsenic Suboxide
      Arsenious Oxide
      Aluminium Arsenite
      Ammonium Arsenites
      Antimony Arsenite
      Barium Arsenites
      Beryllium Arsenite
      Bismuth Arsenite
      Cadmium Arsenites
      Calcium Arsenites
      Chromic Arsenite
      Cobalt Arsenites
      Copper Arsenites
      Gold Arsenites
      Iron Arsenites
      Lead Arsenites
      Lithium Arsenite
      Magnesium Arsenites
      Manganese Arsenites
      Mercury Arsenites
      Nickel Arsenites
      Palladium Pyroarsenite
      Platinum Arsenites
      Potassium Arsenites
      Arsenites of Rare Earth Metals
      Rubidium Metarsenite
      Silver Arsenites
      Sodium Arsenites
      Strontium Arsenites
      Thallous Orthoarsenite
      Tin Arsenites
      Titanyl Tetrarsenite
      Tungsto-arsenites
      Uranyl Metarsenite
      Zinc Arsenites
      Zirconium Arsenite
      Arsenic Tetroxide
      Arsenic Pentoxide
      Aluminium Arsenates
      Ammonium Arsenates
      Barium Arsenates
      Beryllium Arsenates
      Bismuth Arsenates
      Cadmium Arsenates
      Caesium Arsenate
      Calcium Arsenates
      Chromium Arsenates
      Cobalt Arsenates
      Copper Arsenates
      Hydroxylamine Orthoarsenate
      Iron Arsenates
      Lead Arsenates
      Lithium Arsenates
      Magnesium Arsenates
      Manganese Arsenates
      Mercury Arsenates
      Molybdenum Arsenates
      Nickel Arsenates
      Palladium Arsenate
      Platinic Arsenate
      Potassium Arsenates
      Rare Earth Metals Arsenates
      Rhodium Arsenate
      Rubidium Arsenates
      Silver Arsenates
      Sodium Arsenates
      Strontium Arsenates
      Thallium Arsenates
      Thorium Arsenates
      Tin Arsenates
      Titanyl Arsenate
      Tungsto-arsenic Acids
      Uranium Arsenates
      Vanado-arsenates
      Zinc Arsenates
      Zirconium Arsenates
      Perarsenates
      Arsenic and Sulphur
      Arsenic Subsulphide
      Tetrarsenic Trisulphide
      Arsenic Disulphide
      Arsenic Trisulphide
      Arsenic Pentasulphide
      Thioarsenates
      Ammonium Thioarsenates
      Antimony Thioarsenate
      Barium Thioarsenates
      Beryllium Thioarsenate
      Bismuth Thioarsenate
      Cadmium Thioarsenates
      Calcium Thioarsenates
      Cerium Thioarsenates
      Chromium Thioarsenate
      Cobalt Thioarsenate
      Copper Thioarsenates
      Gold Thioarsenates
      Iron Thioarsenates
      Lead Thioarsenates
      Lithium Thioarsenates
      Magnesium Thioarsenates
      Manganese Thioarsenates
      Mercury Thioarsenates
      Molybdenum Thioarsenates
      Nickel Thioarsenates
      Platinic Thioarsenate
      Potassium Thioarsenates
      Silver Thioarsenates
      Sodium Thioarsenates
      Strontium Thioarsenates
      Thallium Orthothioarsenate
      Tin Thioarsenates
      Uranyl Thioarsenate
      Yttrium Thioarsenate
      Zinc Thioarsenates
      Zirconium Thioarsenate
      Trioxythioarsenic Acid
      Dioxydithioarsenic Acid
      Oxytrithioarsenic Acid
      Arsenic Monosulphatotrioxide
      Arsenic Disulphatotrioxide
      Arsenic Trisulphatotrioxide
      Arsenic Tetrasulphatotrioxide
      Arsenic Hexasulphatotrioxide
      Arsenic Octasulphatotrioxide
      Complex salts of Sulphato-compounds of Arsenic
      Arsenic Nitride
      Arsenic Imide
      Arsenic Amide
      Arsenic Phosphides
      Arsenic oxyphosphides
      Arsenic Phosphate
      Arsenic Thiophosphate
      Arsenic Tricarbide
      Arsenic Pentasilicide
      Boron Arsenate
    Detection of Arsenic
    Estimation of Arsenic
    Physiological Properties
    PDB 1b92-1ihu
    PDB 1ii0-1tnd
    PDB 1tql-2hmh
    PDB 2hx2-2xnq
    PDB 2xod-3htw
    PDB 3hzf-3od5
    PDB 3ouu-9nse

Zinc Arsenates





Zinc Orthoarsenate, Zn3(AsO4)2

Zinc Orthoarsenate, Zn3(AsO4)2, has been obtained in the anhydrous form by heating zinc carbonate with aqueous arsenic acid to 200° C. or by fusing a mixture of zinc chloride and arsenic pentoxide. The latter process yields prismatic crystals of density 4.913 at 15° C. The trihydrate, Zn3(AsO4)2.3H2O, is precipitated from zinc sulphate solutions by normal sodium orthoarsenate. The same substance is precipitated in a white voluminous form when excess of alkali is added to solutions of acid zinc arsenates in hydrochloric acid. The octahydrate, Zn3(AsO4)2.8H2O, occurs naturally, associated with cobalt and nickel ores, as kottigite, a pinkish mineral found in Germany in the massive form or in crystalline crusts with a fibrous structure; the crystals are isomorphous with vivianite. The octahydrate may be obtained artificially by adding a soluble arsenate to a solution of a zinc salt, the quantity added being insufficient to remove completely the acidity of the solution; or by mixing solutions of zinc monohydrogen orthoarsenate and zinc sulphate. The precipitate formed is amorphous but, if kept in contact with the solution for some days, the crystalline octahydrate is formed.


Zinc Monohydrogen Orthoarsenate, ZnHAsO4

Zinc Monohydrogen Orthoarsenate, ZnHAsO4.H2O, is obtained as a jelly by treating zinc with excess of aqueous arsenic acid, heating, and filtering at 100° C.; or by mixing solutions of potassium dihydrogen orthoarsenate and zinc sulphate in appropriate proportions. The jelly gradually crystallises on keeping, or when treated with hot water; the crystals are either rhombic or monoclinic. Small white tabular or needle-like crystals of this salt may be prepared by dissolving zinc oxide in aqueous arsenic acid. The salt has also been obtained by prolonged contact between zinc orthophosphate trihydrate and aqueous arsenic acid, and by prolonged digestion at 100° C. of the precipitate obtained by adding ammonium arsenate to a solution of a zinc salt.

An acid salt, of composition 5ZnO.2As2O5.4H2O, has been obtained as a precipitate by mixing aqueous solutions of zinc sulphate and sodium orthoarsenate. It loses one quarter of its water at 100° C. By heating the monohydrogen orthoarsenate in a sealed tube at 200° C. rhombic crystals of composition 5ZnO.2As2O5.nH2O, probably Zn3(AsO4)2.2ZnHAsO4.(n-1)H2O, are obtained.

Zinc Metarsenate, Zn(NaO3)2

Zinc Metarsenate, Zn(NaO3)2, has been described as a heavy white powder formed by allowing zinc orthoarsenate trihydrate to remain in contact with aqueous arsenic acid for more than a year and then filtering the solution.

Zinc Pyroarsenate, Zn2As2O7

Zinc Pyroarsenate, Zn2As2O7, is obtained by dissolving zinc oxide in molten potassium metarsenate. It yields tabular crystals isomorphous with manganese pyroarsenate. The salt is decomposed by water. A basic salt, of composition Zn(OH)2.Zn2As2O7.7H2O, has been obtained by mixing solutions of zinc orthoarsenate and zinc acetate, and boiling the precipitate with water for several weeks; silky crystalline needles are finally obtained, from which all the water may be expelled at 300° C.

Basic salts

The basic salt 4ZnO.As2O5.H2O is produced when zinc monohydrogen orthoarsenate crystals are heated with water. It occurs naturally as adamite, which may be green, yellow, violet or colourless and is usually formulated Zn(Zn.OH)AsO4. Legrandite, a bright yellow transparent mineral associated with massive blende in Mexico, has a composition approximating to Zn14(OH)(AsO4)9.12H2O.

The following double arsenates have been described: NaZnAsO4, Na2ZnAs2O7, K2Zn2As2O8 and NH4ZnAsO4.
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