Antimony trioxide

Arsenic trioxide or Arsenic III oxide or Arsenous acid is an inorganic compound and medication. As an industrial chemical, major uses include in the manufacture of wood preservatives, pesticides, and glass.

General Properties and Specifications of Arsenic trioxide or Arsenic III oxide or Arsenous acid:
Appearance: Almost white powder.
Assay: 99%
Residue on ignition: 0.05%
Relative density: around 3.74
Melting point: 312C literature.
Boiling point: 465C literature.
Solubility: Sparingly soluble in water, soluble in solutions of alkali hydroxides (NaOH 1M). Practically insoluble in ethanol, chloroform, and ethyl ether.

Arsenious Trioxide BP Ph Eur Grade for Homoeopathic Preparations:
As2O3 --- 197.8 --- 1327-53-3

DEFINITION
Content: 99.5 per cent to 100.5 per cent of As2O3.

CHARACTERS
Appearance: White or almost white powder.
Solubility: Practically insoluble to sparingly soluble in water. It dissolves in solutions of alkali hydroxides and carbonates.

IDENTIFICATION
A. Dissolve 20 mg in 1 mL of dilute hydrochloric acid, add 4 mL of water and 0.1 mL of sodium sulfide solution. The resulting yellow precipitate is soluble in dilute ammonia.
B. Dissolve 20 mg in 1 mL of hydrochloric acid, add 5 mL of hypophosphorous reagent and heat for 15 min on a water-bath. A black precipitate develops.

TESTS
Appearance of solution: A 100 g/L solution in dilute ammonia is clear and colourless.
Sulfides: Maximum 20 ppm.

ASSAY
Dissolve 40.0 mg in a mixture of 10 mL of water and 10 mL of dilute sodium hydroxide solution. Add 10 mL of dilute hydrochloric acid and 3 g of sodium hydrogen carbonate and mix. Add 1 mL of starch solution and titrate with 0.05 M iodine.
1 mL of 0.05 M iodine is equivalent to 4.946 mg of As2O3.

Arsenic Trioxide Analytical Reagent Grade:
Arsenic(III) Oxide, Reductometric Standard
As2O3 --- Formula weight 197.84
CAS Number 1327-52-3

REQUIREMENTS
Assay: 99.95-100.05% As2O3

MAXIMUM ALLOWABLE
Residue after ignition: 0.02%
Insoluble in dilute hydrochloric acid: 0.01%
Chloride (Cl): 0.005%
Sulfide (S): Passes test
Antimony (Sb): 0.05%
Lead (Pb): 0.002%
Iron (Fe): 5 ppm