| 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; |
| DERIVATION |
|
|
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 |