Sodium Thiosulfate Pentahydrate (Na2S2O3),
also spelled Sodium Thiosulphate Pentahydrate, is a colorless crystalline compound
that is more familiar as the pentahydrate, Na2S2O3•5H2O.
It
is
an efflorescent, monoclinic crystalline substance also called Sodium Hyposulphite or “Hypo.”
Na2S2O3,5H2O
Sodium
Thiosulphate BP
DEFINITION
Content
99.0 per cent to 101.0 per cent of Na2S2O3,5H2O.
CHARACTERS
Appearance
Transparent, colourless crystals, efflorescent in dry air.
Solubility
Very soluble in water, practically insoluble in ethanol 96 per cent. It
dissolves in its water of crystallization at about 49 °C.
IDENTIFICATION
A.
It decolorizes iodinated potassium iodide solution.
B.
To 0.5 ml of solution S (see Tests) add 0.5 ml of water R and 2 ml of silver nitrate solution. A white precipitate is formed which rapidly becomes
yellowish and then black.
C.
To 2.5 ml of solution S add 2.5 ml of water and 1 ml of hydrochloric
acid. A precipitate of sulphur is formed and gas is evolved which gives a blue colour to starch iodate paper.
D.
1 ml of solution S gives reaction of sodium.
TESTS
Solution S
Dissolve 10.0 g in
carbon
dioxide-free water R prepared from distilled water R and dilute to
100 ml with the same solvent.
Appearance of solution
The freshly prepared solution
is clear and colourless.
Dissolve 10.0 g in 50 ml of
distilled water, add 1 ml of 0.1 M sodium hydroxide and dilute to 100
ml with the same solvent.
pH
6.0 to 8.4 for the freshly
prepared solution S.
Sulphates and sulphites
Maximum 0.2 per cent.
Sulphides
To 10 ml of solution S add
0.05 ml of a freshly prepared 50 g/l solution of sodium nitroprusside. The
solution does not become violet.
Heavy metals
Maximum 10 ppm.
ASSAY
Dissolve Sodium Thiosulfate 0.500 g in 20 ml of
water and titrate with 0.05 M iodine, using 1 ml of starch solution,
added towards
the end of the titration, as indicator.
1 ml of 0.05 M iodine
is equivalent to 24.82 mg of Na2S2O3,5H2O.
We can give both the grades Pentahydrate and Anhydrous.
We can give the technical grade small crystals and large crystals too.
We offer
Sodium Thiosulphate IP, Sodium Thiosulphate BP, Sodium Thiosulfate USP, and
Sodium Thiosulfate Extra Pure from our world class FDA approved, ISO-9001-2008 Certified facility, Anmol Chemicals
Information on IP, BP, USP, ACS, Food Grade
is provided by manufacturer on
Hypo USP ACS AR BP IP Food Grade
Sodium Thiosulphate BP Grade;
Sodium Thiosulphate
BP manufacturers:
MUBY CHEMICALS
S-8, SARIFA MANSION, 2ND FLANK ROAD, CHINCHBUNDER, MUMBAI 400009, INDIA
TEL: (OFFICE) 91-22-23770100, 23726950, 23774610, 23723564. FAX:
91-22-23728264
e-mail:
info@mubychem.com
Cell Call
to Anmol: +91-9821870100
USA & Canadian Customers may Call
773-829-5811
Copyright
and
Usual Disclaimer
is Applicable.
Last
updated:
23 October, 2011.
IT IS NICE TO BE IMPORTANT BUT ….... BUT
IT IS MORE IMPORTANT TO BE NICE
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Uses of Sodium Thiosulfate
Pentahydrate or Sodium Thiosulphate Pentahydrate
Sodium thiosulfate is used in
Iodometry.
It is used for Gold
Extraction.
It is used in Analytical
Chemistry.
It is an antitode to Cyanide
poisioning.
It is a component in hand warmers and
other chemical heating pads that produce heat by exothermic
crystallization of a super cooled solution.
Sodium thiosulphate is used in Bleach.
In pH testing of bleach
substances.
To de-chlorinate tap water for
aquariums or treat effluent from waste water treatments prior to release
into rivers. The
amount of Sodium thiosulfate required can vary with the pH of the
water. A range of approximately 2 to 7 parts sodium thiosulfate to
neutralize one part chlorine is generally suggested. To
neutralize 1 liter of a 200 ppm chlorine solution, approximately 0.4 -
1.4 grams of sodium thiosulfate would be required.
It is used to lower chlorine levels in
swimming pools and spas following super chlorination.
It is used to remove iodine stains, e.g.
after the explosion of nitrogen triiodide.
Sodium thiosulfate is used in bacteriological water
assessment.
It is used in the tanning of leather.
Melted sodium thiosulfate is very easy
to overcool to room temperature and when crystallization is forced, the
sudden temperature jump to 48.3°C can be experienced by touch. It is
used in phase change material.
It is used in paper industry.
It is used in medicine and as disinfectant.
A low amount can be found in natural hot springs water, but
they do have trace sodium sulfide too, which is why it can used to treat
skin problems and some bathe in it to relieve them of skin problems,
rheumatism, although indirectly. It is
systemically for cyanide or arsenic poisoning and topically as an
antifungal.
It is used in electroplating.
As part of patina recipes for
copper alloys.
Often used in pharmaceutical
preparations as an anionic surfactant to aid in dispersion.
