Sodium percarbonate or sodium carbonate peroxide is a chemical substance with formula Na2H3CO6. It is an adduct of sodium carbonate ("soda ash" or "washing soda") and hydrogen peroxide (that is, a perhydrate) whose formula is more properly written as 2 Na2CO3 · 3 H2O2. It is a colorless, crystalline, hygroscopic and water-soluble solid.[3] It is sometimes abbreviated as SPC. It contains 32.5% by weight of hydrogen peroxide.
The product is used in some eco-friendly bleaches and other cleaning products.[3]
Sodium percarbonate was first prepared in 1899 by Ukrainian chemist Sebastian Moiseevich Tanatar (7 October 1849 – 30 November 1917).[4]
At room temperature, solid sodium percarbonate has the orthorhombic crystal structure, with the Cmca crystallographic space group. The structure changes to Pbca as the crystals are cooled below about −30 °C.[1]
Dissolved in water, sodium percarbonate yields a mixture of hydrogen peroxide (which eventually decomposes to water and oxygen), sodium cations (Na+
), and carbonate (CO2−
3).[3][5]
Sodium percarbonate is produced industrially by crystallization of a solution of sodium carbonate and hydrogen peroxide, with proper control of the pH and concentrations.[6][1][7] This is also a convenient laboratory method.
Alternatively, dry sodium carbonate may be treated directly with concentrated hydrogen peroxide solution.[8]
It may also be formed from a process starting from sodium peroxide; when absolute ethyl alcohol reacts with sodium peroxide at 0 °C, a perhydroxide is produced.[citation needed]
Carbon dioxide converts it into sodium hydrogen percarbonate.
World production capacity of this compound was estimated at several hundred thousand tons for 2004.[9]
As an oxidizing agent, sodium percarbonate is an ingredient in a number of home and laundry cleaning products, including non-chlorine bleach products such as Oxyper, OxiClean, Tide laundry detergent,[3] and Vanish.[5]
Many commercial products mix a percentage of sodium percarbonate with sodium carbonate. The average "Oxy" product in the supermarket contains 35–40% sodium percarbonate with about 5% active oxygen when titrated.
Sodium percarbonate is also used as a cleaning agent in homebrewing.[10]
Sodium percarbonate can be used in organic synthesis as a convenient source of anhydrous H2O2, in particular in solvents that cannot dissolve the carbonate but can leach the H2O2 out of it.[11] A method for generating trifluoroperacetic acid in situ for use in Baeyer–Villiger oxidations from sodium percarbonate and trifluoroacetic anhydride has been reported; it provides a convenient and cheap approach to this reagent without the need to obtain highly concentrated hydrogen peroxide.[12][13]
{{cite encyclopedia}}
: CS1 maint: multiple names: authors list (link)