Sodium percarbonate


Sodium percarbonate is a chemical substance with formula. It is an adduct of sodium carbonate and hydrogen peroxide whose formula is more properly written as 2 · 3 . It is a colorless, crystalline, hygroscopic and water-soluble solid. 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, and as a laboratory source of anhydrous hydrogen peroxide.

History

Sodium percarbonate was first prepared in 1899 by Russian chemist Sebastian Moiseevich Tanatar.

Structure

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.

Chemistry

Dissolved in water, sodium percarbonate yields a mixture of hydrogen peroxide, sodium cations, and carbonate.

Production

Sodium percarbonate is produced industrially by crystallization of a solution of sodium carbonate and hydrogen peroxide, with proper control of the pH and concentrations. This is also a convenient laboratory method.
Alternatively, dry sodium carbonate may be treated directly with concentrated hydrogen peroxide solution.
World production capacity of this compound was estimated at several hundred thousand tons for 2004.

Uses

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, and Vanish.
Many commercial products mix a percentage of sodium percarbonate with sodium carbonate. The average percentage of an "Oxy" product in the supermarket is 65% sodium percarbonate and 35% sodium carbonate. The "ultra boosters" seen on infomercials may contain as much as 80% sodium percarbonate. However, sodium percarbonate is less expensive in its pure form and can be adjusted to any percentage the user desires.
Sodium percarbonate is also used as a no-rinse cleaning agent in at-home breweries.
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. 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.