Sodium thiosulfate , 99.99%metalsbasis , 7772-98-7

Synonym(s):
Sodium thiosulfate;Sodium thiosulphate;Sodium thiosulfate pentahydrate;Sodium hyposulfite;Hypo

CAS NO.：7772-98-7

Empirical Formula: Na2O3S2

Molecular Weight: 158.11

MDL number: MFCD00003499

EINECS: 231-867-5

PRODUCT Properties

• Melting point: 48°C
• Boiling point: 100°C
• Density: 1.01 g/mL at 25 °C
• storage temp.: Store at +5°C to +30°C.
• solubility: Immiscible with alcohol.
• form: Solid
• Specific Gravity: 1.667
• color: White
• PH: 6.0-8.5 (25℃, 50mg/mL in H2O)
• Water Solubility: Soluble in water. Insoluble in alcohol.
• Sensitive: Hygroscopic
• Merck: 14,8694
• Stability: Stable. Incompatible with strong acids, strong oxidizing agents, iodine, mercury.
• InChIKey: AKHNMLFCWUSKQB-UHFFFAOYSA-L
• LogP: -0.428 (est)

Description and Uses

Sodium thiosulfate (thiosulfate) Known simply as “hypo,” an abbreviated form of the incorrect form hyposulfite, this white crystal was made by boiling calcium thiosulfate with sodium sulfate. It is soluble in water and oil of turpentine but not in alcohol. The property of sodium thiosulfate to dissolve silver halides was discovered in 1819 by Sir John Herschel and was probably first used to fix photographic images by L. J. M. Daguerre. After Daguerre published its use in his 1839 manual W. H. F. Talbot finally used it to fix calotype negatives and silver chloride prints, although he continued to stabilize them with potassium iodide and sodium chloride presumably for the variety of colors possible. Sodium thiosulfate was the primary fixing agent throughout the 19th century and is still used today.

Safety

• Symbol(GHS): GHS07
• Signal word: Warning
• Hazard statements: H335-H315-H319
• Precautionary statements: P264-P280-P305+P351+P338-P337+P313P-P264-P280-P302+P352-P321-P332+P313-P362
• Hazard Codes: Xi
• Risk Statements: 36/37/38
• Safety Statements: 24/25-23-36-26
• WGK Germany: 1
• RTECS: XN6476000
• F: 3
• TSCA: Yes
• HS Code: 28323000
• Toxicity: LD50 orally in Rabbit: > 5000 mg/kg