CAS
NO. |
7772-98-7 (Anhydrous) 10102-17-7
(Pentahydrate) |
|
EINECS
NO. |
231-867-5 |
FORMULA |
Na2O3S2 |
MOL
WT. |
158.10 |
H.S.
CODE
|
|
TOXICITY |
|
SYNONYMS |
Thiosulfuric acid,
disodium salt; Sodium Oxide Sulfide; |
antichlor; HYPO; Hyporice; Sodium hyposulfite; sodium
subsulfite; |
SMILES |
|
CLASSIFICATION
|
|
PHYSICAL
AND CHEMICAL PROPERTIES (Anhydrous)
|
PHYSICAL
STATE |
White crystals
or powder |
MELTING
POINT |
43 C |
BOILING
POINT |
|
SPECIFIC
GRAVITY |
1.667 |
SOLUBILITY
IN WATER |
Soluble
(33%) |
pH |
6.5
- 8 |
VAPOR
DENSITY |
|
AUTOIGNITION
|
|
NFPA
RATINGS
|
Health: 2; Flammability: 0; Reactivity: 0 |
REFRACTIVE
INDEX
|
|
FLASH
POINT |
|
STABILITY |
Stable
under ordinary conditions. Hygroscopic. |
GENERAL
DESCRIPTION & APPLICATIONS
|
Sodium Thiosulfate is a white translucent crystals or powder that is common as
the pentahydrate form; melting at 48 C; readily soluble in water and oil of
turpentine; aqueous solution is slightly alkaline which decompose to sulfate and
sulfide in the air. It is a moderate reducing agent. It is a source of
thiosulfate ion (S2O3-2) (dissolves silver salts). Its major use is as a
fixing agent in photography for developing film and the extracting silver from
ore. It is used in chrome-tanning leather and in chemical manufacture as a
source of sulfide ion. It is also used in paper, textile, water treatment
industry and gas purification. |
SALES
SPECIFICATION |
ANHYDROUS
TECH GRADE
|
APPEARANCE
|
white
to off-white crystalline powder |
Na2S2O3 |
97.5%
min
|
HEAVY METALS |
20ppm
max |
ANHYDROUS
PHOTO GRADE
|
Na2S2O3 |
98.5%
min |
Na2SO3 |
0.5%
max
|
NaOH |
0.01%
max
|
SULFIDE |
2ppm max |
Fe
|
10ppm
max |
HEAVY METALS |
10ppm
max
|
FREE
ACID
|
20ppm
max
|
INSOLUBLES MATTER |
0.5%
max
|
PENTAHYDRATE
|
Na2S2O3•H2O |
99.5%
min
|
Fe
|
10ppm
max
|
HEAVY METALS |
10ppm
max
|
FREE
ACID
|
0.01%
max
|
NaOH
|
0.015%
max
|
INSOLUBLES MATTER |
0.2%
max
|
30%
SOLUTION
|
Na2S2O3 |
29.0
- 31.0%
|
pH
|
6.5 - 9 |
TRANSPORTATION
|
PACKING |
25kgs,
50kgs, 1mt in Bag |
HAZARD
CLASS |
Not
regulated |
UN
NO. |
|
OTHER
INFORMATION |
Hazard
Symbols: n/a, Risk Phrases: n/a, Safety Phrases: 24/25
|