Ammonium thiosulfate

Structural formula
2
General
Surname	Ammonium thiosulfate
other names	ATS
Molecular formula	(NH 4 ) 2 S 2 O 3
Brief description	white odorless solid
External identifiers / databases
CAS number 7783-18-8 EC number 231-982-0 ECHA InfoCard 100,029,074 PubChem 6857883 Wikidata Q421453
properties
Molar mass	148.21 g mol −1
Physical state	firmly
density	1.679 g cm −3
Melting point	150 ° C (decomposition)
solubility	Easily soluble in water (1033 g l −1 at 100 ° C) almost insoluble in ethanol
safety instructions
GHS labeling of hazardous substances no GHS pictograms H and P phrases H: no H-phrases P: no P-phrases
Toxicological data	2890 mg kg −1 ( LD 50 ,  rat ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Ammonium thiosulfate is a chemical compound from the group of ammonium salts and inorganic thiosulfates .

Extraction and presentation

Ammonium thiosulphate can be obtained by reacting ammonium sulphite with sulfur or sulphides in aqueous solutions (partly with ammonia), oxidation of hydrogen sulphide , through reaction of ammonium hydrogen carbonate with sulfur dioxide .

${\displaystyle {\rm {\ 2\ NH_{3}+SO_{2}+H_{2}O\rightarrow (NH_{4})_{2}SO_{3}}}}$

${\displaystyle {\rm {\ 2\ NH_{4}HCO_{3}+SO_{2}+H_{2}O\rightarrow (NH_{4})_{2}SO_{3}+2\ H_{2}O+2\ CO_{2}\uparrow }}}$

${\displaystyle {\rm {\ (NH_{4})_{2}SO_{3}+S\rightarrow (NH_{4})_{2}S_{2}O_{3}}}}$

properties

Ammonium thiosulfate decomposes above 150 ° C, producing sulfur oxides, ammonia and nitrogen oxides.

use

Ammonium thiosulphate is used as a quick fixing salt (similar to sodium thiosulphate ) for the production of fixing baths in film technology, photo technology and X-ray technology and as a fertilizer.

Web links

• Reclaimed silver from fixing baths, photographic films and papers (junker-Edelmetalle)

Individual evidence

1. ↑ ^{a b c d e f g h i} Entry on ammonium thiosulphate in the GESTIS substance database of the IFA , accessed on December 22, 2019 (JavaScript required)
2. ↑ Data sheet ammonium thiosulfate (PDF) from Merck , accessed on March 17, 2010.
3. ^ Karl Heinz Büchel, Hans-Heinrich Moretto, Peter Woditsch: Industrial Inorganic Chemistry. ISBN 978-3-527-29849-5 .
4. ↑ Process for the production of ammonium thiosulfate (Patent.de)
5. ↑ Safety data sheet (fld-friedland)  ( page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF; 45 kB)