Peroxymonosulfuric acid, also known as persulfuric acid, peroxysulfuric acid is the

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

with the formula . It is a white solid. It is a component of Caro's acid, which is a solution of peroxymonosulfuric acid in

sulfuric acid Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...

containing small amounts of water. Peroxymonosulfuric acid is a very strong oxidant ( ''E''⁰ = +2.51 V).

Structure

In peroxymonosulfuric acid, the S(VI) center adopts its characteristic tetrahedral geometry; the connectivity is indicated by the formula HO–O–S(O)₂–OH. The S-O-''H'' proton is more acidic.

History

The German chemist

Heinrich Caro Heinrich Caro (February 13, 1834 – September 11, 1910) was a German chemist. Caro was of Sephardic Jewish origin He started his study of chemistry at the Humboldt University of Berlin, Friedrich Wilhelms University and later chemistry and dy ...

first reported investigations of mixtures of hydrogen peroxide and sulfuric acid.

Synthesis and production

One laboratory scale preparation of Caro's acid involves the combination of

chlorosulfuric acid Chlorosulfuric acid (IUPAC name: sulfurochloridic acid) is the inorganic compound with the formula HSO3Cl. It is also known as chlorosulfonic acid, being the sulfonic acid of chlorine. It is a distillable, colorless liquid which is hygroscopic and ...

and

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscosity, viscous than Properties of water, water. It is used as an oxidizer, bleaching agent, and antiseptic, usua ...

: : Patents include more than one reaction for preparation of Caro's acid, usually as an intermediate for the production of potassium monopersulfate (PMPS), a bleaching and oxidizing agent. One route employs the following reaction: : This reaction is related to "

piranha solution Piranha solution (), also known as piranha etch, is a mixture of sulfuric acid () and hydrogen peroxide (). The resulting mixture is used to clean organic residues off substrates, for example silicon wafers. Because the mixture is a strong o ...

Uses in industry

and Caro's acid have been used for a variety of disinfectant and cleaning applications, e.g., swimming pool treatment and denture cleaning. It is used in

gold mining Gold mining is the extraction of gold by mining. Historically, mining gold from Alluvium, alluvial deposits used manual separation processes, such as gold panning. The expansion of gold mining to ores that are not on the surface has led to mor ...

to destroy the

cyanide In chemistry, cyanide () is an inorganic chemical compound that contains a functional group. This group, known as the cyano group, consists of a carbon atom triple-bonded to a nitrogen atom. Ionic cyanides contain the cyanide anion . This a ...

in the waste stream ("

Tailings In mining, tailings or tails are the materials left over after the process of separating the valuable fraction from the uneconomic fraction (gangue) of an ore. Tailings are different from overburden, which is the waste rock or other material ...

"). Alkali metal salts of , especially

oxone Potassium peroxymonosulfate is widely used as an oxidizing agent, for example, in pools and spas (usually referred to as monopersulfate or "MPS"). It is the potassium salt of peroxymonosulfuric acid. Potassium peroxymonosulfate per se is rarely e ...

, are widely investigated.

Hazards

These peroxy acids can be explosive. Explosions have been reported at

Brown University Brown University is a Private university, private Ivy League research university in Providence, Rhode Island, United States. It is the List of colonial colleges, seventh-oldest institution of higher education in the US, founded in 1764 as the ' ...

and Sun Oil. As with all strong oxidizing agents, peroxysulfuric acid is incompatible with

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

References