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Ammonium persulfate

Names
Other names Ammonium peroxydisulfate
Identifiers
CAS Number	7727-54-0
3D model (JSmol)	Interactive image Interactive image
ChemSpider	56400
ECHA InfoCard	100.028.897
EC Number	231-786-5
E number	E923 (glazing agents, ...)
RTECS number	SE0350000
UNII	22QF6L357F
UN number	1444
CompTox Dashboard (EPA)	DTXSID9029691
InChI InChI=1S/2H3N.H2O8S2/c;;1-9(2,3)7-8-10(4,5)6/h2*1H3;(H,1,2,3)(H,4,5,6)Key: ROOXNKNUYICQNP-UHFFFAOYSA-N InChI=1/2H3N.H2O8S2/c;;1-9(2,3)7-8-10(4,5)6/h2*1H3;(H,1,2,3)(H,4,5,6)Key: ROOXNKNUYICQNP-UHFFFAOYAL
SMILES O=S(=O)()OOS()(=O)=O.. ..S(=O)(=O)OOS(=O)(=O)
Properties
Chemical formula	(NH4)2S2O8
Molar mass	228.18 g/mol
Appearance	white to yellowish crystals
Density	1.98 g/cm
Melting point	120 °C (393 K) decomp.
Solubility in water	80 g/100 mL (25 °C)
Hazards
NFPA 704 (fire diamond)	2 0 2OX
Lethal dose or concentration (LD, LC):
LD50 (median dose)	689 mg/kg, oral (rat)
Related compounds
Other anions	Ammonium thiosulfate Ammonium sulfite Ammonium sulfate
Other cations	Sodium persulfate Potassium persulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C , 100 kPa). Y verify (what is  ?) Infobox references

Ammonium persulfate (APS) is the inorganic compound with the formula (NH₄)₂S₂O₈. It is a colourless (white) salt that is highly soluble in water, much more so than the related potassium salt. It is a strong oxidizing agent that is used in polymer chemistry, as an etchant, and as a cleaning and bleaching agent.

The dissolution of the salt in water is endothermic. When APS dissolves in water, it breaks down into ammonia and peroxydisulfuric acid.

Preparation

Ammonium persulfate is prepared by electrolysis of a cold concentrated solution ammonium sulfate in sulfuric acid at a high current density. The method was first described by H. Marshall.

Uses

As an oxidizer and a source of radicals, APS finds many commercial applications.

Salts of peroxydisulfate are mainly used as radical initiators in the polymerization of certain alkenes. Commercially important polymers prepared using persulfates include styrene-butadiene rubber and polytetrafluoroethylene. In solution, the dianion dissociates to give radicals:

${\displaystyle {\overrightarrow {\leftarrow }}}$ 2

The sulfate radical adds to the alkene to give a sulfate ester radical. It is also used along with tetramethylethylenediamine to catalyze the polymerization of acrylamide in making a polyacrylamide gel.

Illustrative of its powerful oxidizing properties, it is used to etch copper on printed circuit boards as an alternative to ferric chloride solution. This property was discovered many years ago. In 1908, John William Turrentine used a dilute ammonium persulfate solution to etch copper. Turrentine weighed copper spirals before placing the copper spirals into the ammonium persulfate solution for an hour. After an hour, the spirals were weighed again and the amount of copper dissolved by ammonium persulfate was recorded. This experiment was extended to other metals such as nickel, cadium, and iron, all of which yielded similar results.

Ammonium persulfate is the main component of Nochromix, a laboratory cleaning agent. On dissolving in sulfuric acid, it is used to clean laboratory glassware as a metal-free alternative to chromic acid baths. It is also a standard ingredient in western blot gels and hair bleach.

Persulfates are used as oxidants in organic chemistry.

Safety

Airborne dust may be irritating to eye, nose, throat, lung and skin upon contact. Exposure to high levels of dust may cause difficulty in breathing.

It has been noted that persulfate salts are a major cause of asthmatic effects in women. Furthermore, it has been suggested that exposure to ammonium persulfate can cause asthmatic effects in hair dressers and receptionists working in the hair dressing industry. These asthmatic affects are proposed to be caused by the oxidation of cysteine residues, as well as methionine residues.

References

1. F. Feher, "Potassium Peroxydisulfate" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 390.
2. Hugh Marshall (1891). "LXXIV. Contributions from the Chemical Laboratory of the University of Edinburgh. No. V. The persulphates". J. Chem. Soc., Trans. 59: 771. doi:10.1039/CT8915900771.
3. Harald Jakob, Stefan Leininger, Thomas Lehmann, Sylvia Jacobi, Sven Gutewort. "Peroxo Compounds, Inorganic". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a19_177.pub2. ISBN 978-3527306732.{{cite encyclopedia}}: CS1 maint: multiple names: authors list (link)
4. "Ammonium Persulphate: Copper Etchant". MG Chemicals.
5. Turrentine, J. W. (1908). "Action of Ammonium Persulphate on Metals". Journal of Physical Chemistry. 11: 623–631.
6. "Nochromix". Sigma-Aldrich. Retrieved 2008-03-01.
7. Encyclopedia of Reagents for Organic Synthesis, vol. 1, pp. 193–197 (1995).
8. FMC Corporation, MSDS sheet dated: 06/26/2009
9. De Vooght, V.; Jesus Cruz, M.; Haenen, S.; Wijnhoven, K.; Munoz, X.; Cruz, M.; Munoz, X.; Morell, F.; Nemery, B (2010). "Ammonium persulfate can initiate an asthmatic response in mice". Thorax. 65: 252–257.{{cite journal}}: CS1 maint: multiple names: authors list (link)
10. Pignatti, P.; Frossi, B.; Pala, G.; Negri, S.; Oman, H.; Perfetti, L.; Pucillo, C.; Imbriani, M.; Moscato, G. (2013). "Oxidative activity of ammonium persulfate salt on mast cells and basophils: implication in hairdressers' asthma". Int. Arch. Allergy Immunol. 160: 409–419.{{cite journal}}: CS1 maint: multiple names: authors list (link)

External links

• International Chemical Safety Card 0632

• Persulfates
• Peroxides
• Ammonium compounds
• Oxidizing agents