CAS NO.:10102-17-7
Molecular Formula:Na2S2O3?5H2O
Structural Formula:
Molecular Weight:248.19
Product standard:
Ndustrial grade: HG/T 2328-2006
Photographic grade: HG/T 3023-1989
Medicinal grade: ChP. 2020
Specifications:
Industrial grade |
Photographic grade |
Medicinal grade |
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Items
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Specifications |
Specifications |
Specifications |
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Superior products |
Qualified products |
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Appearance |
Colorless or yellowish transparent monoclinic crystals. |
Solution appearance: Transparent without insoluble substances (excluding trace flocculent substances) |
Character: This product is colorless, transparent crystal or crystalline fine particles; Odorless; |
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Sodium thiosulfate(Na2S2O3·5H2O)/% |
≥99.0% |
≥98.0% |
99.0~101.0 |
≥ 99.0%, calculated as dry product |
Water-insoluble substance/% |
≤0.01% |
≤0.03% |
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/ |
Sulfate and Sulfite/% |
/ |
/ |
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≤0.2% |
Sulfides(as Na2S)/% |
≤0.001% |
≤0.003% |
≤0.001 |
≤0.0005% |
Iron(Fe)/% |
≤0.002% |
≤0.003% |
≤0.003 |
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Sodium chloride(NaCl)/% |
≤0.05% |
≤0.20% |
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/ |
pH(200g/L solution)(20℃) |
6.5~9.5 |
6.0~8.4 |
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Heavy metals(as Pb)/% |
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/ |
≤10ppm |
≤20ppm |
Arsenic/% |
/ |
/ |
/ |
≤10ppm |
Loss on drying/% |
/ |
/ |
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32.0%-37.0% |
Packaging: Medicinal grade 25kg cardboard drum; Industrial grade: 25kg, 50kg plastic woven bags; Photographic grade: plastic bucket, IBC bucket, liquid bag, tank truck, etc.
Uses: Medicinal grade: Antidote; Photographic grade: mainly used as a fixing agent in the photography industry; Industrial grade: used as reducing agent of chromate in tanning, neutralizer of nitrogen containing tail gas, mordant, bleaching agent of straw and wool, and dechlorination agent in pulp bleaching. It is also used in the manufacturing of tetraethyl lead, dye intermediates, and ore extraction of silver;