Specification:
Na2S2O3 99.0% min
Insolubles in water 0.01% max
Na2S 0.003%max
Fe 0.003%max
Particle size (grain/gram) 15-18
Item |
Photographic grade |
Industrial grade |
Anhydrous grade |
Appearance |
colorless transparent crystal |
Colorless transparent crystal |
white powder |
Assay |
≥99.00% |
≥98.5% |
≥97.0% |
Water Insoluble matter |
≤0.01% |
≤0.03% |
≤0.03% |
Sulfide |
≤0.001% |
≤0.003% |
≤0.001% |
Fe |
≤0.001% |
≤0.003% |
≤0.005% |
PH |
6.5~9.5 |
6.5~9.5 |
6.5~9.5 |
Water solution reaction |
in accordance with the test |
in accordance with the test |
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Granularity(g/g) |
12~16 |
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Molecular formula: Na2S2O3.5H2O
Molecular Weight: 248.17
Application: used as photo fixing solution, dechlorination agent and printing and dyeing assistant after bleaching cotton fabric, also used in medicine, electroplating, tanning, metallurgy, dyestuff and so on
Packing storage: packing with woven bag lined with polyethylene plastic bag or wooden barrel.The net weight per bag (drum) is 25kg or 50kg.Containers must be sealed.Store in a cool and dry warehouse, prevent from being exposed to the sun and rain during transportation.It should not be stored and transported together with acids and oxidants.Prevent moisture from melting.If the package is damp, it means that the contents have become desiccated and must be stacked separately from the dry package.Can not be stored in the open air, on the damp package to handle.In case of fire, water and sand can be used.
Physicochemical properties: white monoclinic crystal.No smell, cool and bitter taste.Relative density 1.729 (17ºC).Melting point 40 ~ 45ºC.Heat to 100ºC and lose 5 crystalline water.Soluble in water, aqueous solution nearly neutral.Soluble in turpentine and ammonia.Insoluble in alcohol.Deliquescence in moist air.Easy weathering in dry air above 33ºC.It's reductive.It dissolves halogens and silver salts.