Sodium persulfate is the inorganic compound with the formula Na2S2O8. It is the sodium salt of peroxydisulfuric acid, H2S2O8, an oxidizing agent. It is a white solid that dissolves in water. It is almost non-hygroscopic and has good shelf-life.
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||238.10 g/mol|
(Loose bulk density: 1.12 g/cm3)
|Melting point||180 °C (356 °F; 453 K) decomposes|
|55.6 g/100 ml (20 °C)|
|Safety data sheet||ICSC 1136|
|GHS Signal word||Danger|
|H272, H302, H315, H317, H319, H334, H335, H371|
|P220, P261, P280, P305+351+338, P342+311|
|NFPA 704 (fire diamond)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
The salt is prepared by the electrolytic oxidation of sodium hydrogen sulfate:
- 2 NaHSO4 → Na2S2O8 + H2
The standard redox potential of sodium persulfate into hydrogen sulfate is 2.1 V, which is higher than that of hydrogen peroxide (1.8 V) but lower than ozone (2.2 V). The sulfate radical formed in situ has a standard electrode potential of 2.7 V.
However, there are a few drawbacks in utilizing platinum anodes to produce the salts; the manufacturing process is inefficient due to oxygen evolution and the product could contain contaminants coming from platinum corrosion (mainly due to extremely oxidizing nature of the sulfate radical). Thus, boron-doped diamond electrodes have been proposed as alternatives to the conventional platinum electrodes.
It is mainly used as a radical initiator for emulsion polymerization reactions for styrene based polymers such as Acrylonitrile butadiene styrene. Also applicable for accelerated curing of low formaldehyde adhesives.
It is a bleach, both standalone (particularly in hair cosmetics) and as a detergent component. It is a replacement for ammonium persulfate in etching mixtures for zinc and printed circuit boards, and is used for pickling of copper and some other metals.
Sodium persulfate is a specialized oxidizing agent in chemistry, classically in the Elbs persulfate oxidation and the Boyland–Sims oxidation reactions. It is also used in radical reactions; for example in a synthesis of diapocynin from apocynin where iron(II) sulfate is the radical initiator.
The salt is an oxidizer and forms combustible mixtures with organic materials such as paper.
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- Shafiee, Saiful Arifin; Aarons, Jolyon; Hairul Hisham, Hamzah (2018). "Electroreduction of Peroxodisulfate: A Review of a Complicated Reaction". Journal of the Electrochemical Society. ECS. 165 (13): H785–H798. doi:10.1149/2.1161811jes.
- Wacławek, S., Lutze, H. V., Grübel, K., Padil, V.V.T., Černík, M., Dionysiou, D.D. (2017) (2017). "Chemistry of persulfates in water and wastewater treatment: A review". Chemical Engineering Journal. 330: 44–62. doi:10.1016/j.cej.2017.07.132.CS1 maint: multiple names: authors list (link)
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