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

Strontium Arsenates





Strontium Orthoarsenate, Sr3(AsO4)2

Strontium Orthoarsenate, Sr3(AsO4)2, may be prepared by neutralising aqueous arsenic acid with strontia-water, or by adding ammonia to a solution of strontium monohydrogen arsenate in dilute hydrochloric acid; in either case the precipitate is separated and well washed with water. The salt may also be obtained by fusing together equal quantities of sodium chloride and sodium orthoarsenate and adding the required proportion of strontium oxide; after cooling, the sodium salts are removed by washing with water. Colourless rhombic crystals of density 4.601 are obtained, readily soluble in dilute acids. The salt melts at 1635° C. When heated at 400° to 450° C. in hydrogen, reduction occurs to give strontium oxide, arsenic and water.


Strontium Monohydrogen Arsenate, SrHAsO4

Strontium Monohydrogen Arsenate, SrHAsO4, may be prepared as follows: Strontium hydroxide is added slowly and with stirring to a solution of arsenic acid (containing 75 g. As2O5 in 1.5 litres H2O) until a slight turbidity appears. Sodium hydroxide, free from carbonate, is then added to bring the pH to about 5.4, the faintly turbid solution heated in portions of about 150 c.c. and stirred until the monohydrogen orthoarsenate separates in fine crystals. The supernatant liquid is removed, again treated with sodium hydroxide and heated to give a further yield. The crystals are washed with alcohol and dried in air. They usually contain a slight excess of arsenic acid.

The salt may also be obtained by the action of hot water on strontium dihydrogen orthoarsenate or on the pyroarsenate; or by the action of ammonia on a hot solution in hydrochloric acid of the precipitate obtained by mixing solutions of strontium chloride and sodium monohydrogen orthoarsenate. In the last case the anhydrous salt crystallises out, but if the mother liquor is kept in an atmosphere of ammonia, the monohydrate, SrHAsO4.H2O, crystallises out. The density of the latter is 3.606 at 15° C. and of the anhydrous salt 4.035. The monohydrate becomes anhydrous at 130° C. and at a higher temperature yields the pyroarsenate.

Strontium Dihydrogen Orthoarsenate, Sr(H2AsO4)2

Strontium Dihydrogen Orthoarsenate, Sr(H2AsO4)2, may be prepared by adding 24 g. of strontium hydroxide to an aqueous solution of arsenic acid (containing 60 g. As2O5 in 90 c.c.) and heating until a clear solution is obtained. On prolonged boiling, much of the dihydrogen salt crystallises out and, after filtration, a further crop may be obtained from the mother liquor. The crystals should be washed with alcohol and dried. Like the monohydrogen salt they usually contain a slight excess of arsenic acid.

The dihydrate, Sr(H2AsO4)2.2H2O, may be obtained by treating strontium carbonate with an excess of arsenic acid. The crystals lose their water of crystallisation at 240° to 250° C. and on further heating yield strontium metarsenate, Sr(NaO3)2.

Strontium Pyroarsenate, Sr2As2O7

Strontium Pyroarsenate, Sr2As2O7, is formed when the monohydrogen orthoarsenate is heated above 360° C. or when potassium monohydrogen orthoarsenate is fused with strontium oxide or carbonate. It is slightly soluble in mineral acids.

A basic arsenate of composition 3Sr3(AsO4)2.Sr(OH)2 has been obtained as a fine flaky precipitate by the action of sodium hydroxide and strontia-water on an acidified solution of sodium monohydrogen orthoarsenate, care being taken to ensure the absence of carbonate.

Salts of the type MSrAsO4 (where M = NH4, K or Na) have been obtained, as also have the following pyroarsenates, SrCuAs2O7 and SrHgAs2O7.
© Copyright 2008-2012 by atomistry.com