Bariumthiosulfat

Bezeichnung:Bariumthiosulfat

Englisch Name:BARIUM THIOSULFATE

CBNumberCB8131894

SummenformelBaO3S2

Molgewicht249.46

Synonyma

Bariumthiosulfat

Bariumthiosulfat physikalisch-chemischer Eigenschaften

Schmelzpunkt	decomposes at 220℃ [CRC10]
Dichte	3.45
Löslichkeit	insoluble in ethanol
Aggregatzustand	white crystalline powder
Farbe	white crystals, crystalline powder
Wasserlöslichkeit	insoluble EtOH; 0.220 g/100g H2O [CRC10]
Merck	13,1002
Solubility Product Constant (Ksp)	pKsp: 4.79
Expositionsgrenzwerte	ACGIH: TWA 0.5 mg/m3 NIOSH: IDLH 50 mg/m3; TWA 0.5 mg/m3
CAS Datenbank	35112-53-9(CAS DataBase Reference)
EPA chemische Informationen	Thiosulfuric acid (H2S2O3), barium salt (1:1) (35112-53-9)

Sicherheit

Kennzeichnung gefährlicher	Xn
R-Sätze:	20/22
S-Sätze:	28
RIDADR	UN 1564 6.1/PG 3
WGK Germany	1
TSCA	Yes
HazardClass	6.1
PackingGroup	III

Gefahreninformationscode (GHS)

R-Sätze Betriebsanweisung:
R20/22:Gesundheitsschädlich beim Einatmen und Verschlucken.
S-Sätze Betriebsanweisung:
S28:Bei Berührung mit der Haut sofort abwaschen mit viel . . . (vom Hersteller anzugeben).
Beschreibung
Barium thiosulfate has the molecular formula of BaS₂O₃ and the molecular weight of 249.4602 g/mol. It can be prepared by the reaction of sodium thiosulfate in water with the chloride of barium:
BaCl2+Na2S2O3 ? BaS2O3+2NaCl
It is not very soluble in water (0.25 g/100 ml at 15°C) so that the solution does not need to be evaporated at a low temperature to crystallize the product. A monohydrate is the result. BaS₂O₃·H₂O has the CAS number of 35112-53-9. It is insoluble in ethanol. It is a white, crystalline, water-insoluble, poisonous solid. It loses the water of hydration at 110°C and decomposes at 228°C to form the sulfate, sulfur and SO₂.
BaS₂O₃·H₂O is used chiefly in the manufacture of explosives, matches, paints, and varnishes. However,the demand for this chemical is not substantial and it is classified as a “rare” chemical.
Chemische Eigenschaften
White, crystalline powder.Slightly soluble in water; insoluble in alcohol.
Verwenden
Explosives, luminous paints, matches, varnishes, photography.
Verwenden
Barium thiosulfate (BaS2O3) is mainly used in explosives, matches, varnishes, and photography.
läuterung methode
It is very slightly soluble in water and is washed repeatedly with chilled water and dried in air at 40o.