Strontium arsenites

Strontium Arsenites.—An impure strontium orthoarsenite, containing more strontium than corresponds to the formula Sr3(As03)2, has been obtained10 as a white floeculent precipitate by treating strontium chloride solution with potassium orthoarsenite in the cold. If the precipitate is dissolved in a dilute solution of acetic acid, on evaporation strontium hydrogen orthoarsenite, SrHAsOs.H20, is obtained. 

SYNS ARSENIOUS acid, STRONTIUM SALT STRONTIUM ARSENITE, soUd (DOT)... 

Strontium arsenite tetrahydrate Sr(As03)3-4H30 10378-48-0 373.62 wh powder si HjO, EtOH sol dll acid... 

Barium Arsenide, Ba3As2.—By passing arsine over barium oxide at red heat Soubeiran 4 obtained a mixture of arsenide and arsenite. Lebeau 6 prepared the pure arsenide by reduction of barium arsenate with carbon in an electric furnace. Barium arsenide is very similar in properties to the arsenides of calcium and strontium it is slightly darker in colour, more readily fusible and more reactive chemically. Its density at 15° C. is 4-1. It burns spontaneously in fluorine, chlorine or bromine vapour. In oxygen it burns at about 300° C. and in sulphur vapour at dull red heat. 

Strontium Arsenide, Sr3As2, may be prepared by reduction of strontium arsenate. This is best accomplished by rapidly heating with carbon 10 to 1500° to 1600° C. If the heating is slow, reduction begins at about 800° C-. yielding first the arsenite, arsenic then being lost and strontium oxide formed. Calcium arsenate behaves similarly (p. 60). Strontium arsenide forms reddish-brown crystals, transparent in thin... 

Strontium Metarsenite, Sr(As02)2.4H20, may be obtained by the action of ammonium arsenite on a solution of a strontium salt.1 The precipitation is increased by the addition of alcohol, since the arsenite is fairly soluble in water. When dried at 100° C. it has the composition Sr(As02)2.3H20. At higher temperatures it decomposes to form strontium oxide, arsenious oxide and a little arsenic.2 Stavenhagen was unable to obtain the metarsenite in a pure state. 

A solution of 12.6 g. of pure a-methyl-D-glucopyranoside (XXVII) in distilled water is added to 260 cc. of 0.54 M aqueous periodic acid solution (2.1 molecular equivalents). The solution, after being diluted with water to 500 cc., is kept at 20-25° for about twenty-four hours. If desired, the excess periodic acid can be determined by the arsenite method. The rotation of the reaction solution should correspond to [a]i> = +121° calculated for the dialdehyde XXVIII. The solution is neutralized to phenolphthalein with hot strontium hydroxide solution with care to avoid any excess. The precipitate of strontium iodate and strontium periodate is filtered and washed with cold water. After the addition of 1 g. <5f strontium carbonate, the solution is concentrated in vacuum with the water bath at 50° to a volume of about 50 cc., filtered to Temove strontium carbonate, and the concentration (bath, 40°) continued to dryness. The residue is extracted six times with 25-cc. portions of cold absolute ethanol, which separates the dialdehyde completely from slightly soluble strontium salts, as shown by the lack of optical activity of an aqueous solution of these salts. The dialdehyde XXVIII is recovered from the ethanol solution as a colorless syrup in quantitative yield by distillation of the solvent in vacuum with the bath at 40-45°. 

ARSENIOUS ACID, STRONTIUM SALT see SME500 ARSENIOUS ACID, TRISILVER(I-h) SALT see SDMIOO ARSENIOUS ACID, ZINC SALT (9CI) see ZDSOOO ARSENIOUS CHLORIDE see ARF500 ARSENIOUS OXIDE see ARI750 ARSENIOUS SULPHIDE see ARIOOO ARSENIOUS TRIOXIDE see ARI750 ARSENITE see ARI750... 

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