Sodium perborate adalah senyawa kimia yang rumus kimianya dapat ditulis NaH
2 BO
4 , Na
2 H
4 B
2 O
8 , atau, lebih tepatnya, [Na
]
2 Â · [B
2 O
4 (OH)
4 ] 2 -
. Namanya kadang-kadang disingkat sebagai PBS .
This compound is commonly encountered in the form of anhydrous or as hexahydrate (commonly called "monohydrate" or PBS-1 and "tetrahydrate" or PBS-4 , after the initial assumption that NaBO
3 will become anhydrous shape). Both are white, odorless, water soluble.
This salt is widely used in detergents, as one of the peroxide-based bleach.
Video Sodium perborate
Structure
Unlike sodium percarbonate and perfosphate, these compounds are not just additions to hydrogen peroxide. On the contrary, it contains a dianion perborat [(B (OH)
2 OO)
2 ] 2 - consists of a core -BOOBOO- cyclic with two hydroxy groups attached to each boron atom. The ring adopts a chair conformation.
Maps Sodium perborate
Hydrate
Senyawa ini juga mengkristal dari air sebagai hexahydrate, Na
2 H
4 B
2 O
8 Â · 6 H
2 O , yaitu, Na
2 H
16 B
2 O
14 atau NaH
8 BO
7 .
Anhydrous compounds are generally but not properly called "monohydrate" after the original formulation NaBO
3 Ã, Â · H
2 O than Na
2 H
4 B sub style = "font size: inherit; line-height: inherit; vertical-align: baseline"> 2 O
8 . Similarly, hexahydrate is usually called "tetrahydrate" and is formulated as NaBO
3 Ã, Â · 4 H
2 O .
Both shapes are white, odorless, water-soluble solids. The "monohydrate" and "tetrahydrate" are important commercial forms.
Chemistry
Sodium perborate undergoes hydrolysis when in contact with water, producing hydrogen peroxide and borate.
Lebih tepatnya, dalam larutan anion siklik menghidrolisis menjadi dua anion [B (OH)
3 (OOH)] -
, yang kemudian masuk dalam ekuilibrium dengan asam borat B (OH)
3 , hidrogen peroksida H
2 O
2 , anion hydroperoxyl HOO -
, dan anion tetrahydroxyborate [B (OH)
4 ] -
:
- [(B (OH)
2 OO)
2 ] < sup style = "font-size: inherit; line-height: inherit; vertical-align: baseline"> 2 -
2 H < br> 2 O Â <-> 2 [B (OH)
3 (OOH)] -
- [B (OH)
3 (OOH)] -
<-> B (OH) < br> 3 HOO -
- B (OH)
3 HOO -
H
2 O <-> [B (OH)
4 ] -
H < br> 2 O
2
Ketika konsentrasi larutan meningkat, spesies peroxoborate lainnya menjadi signifikan. Dengan kelebihan H
2 O < br> 2 , anions [B (OH)
2 (OOH)
2 ] -
, [B (OH) (OOH)
3 ] -
, dan akhirnya [B (OOH)
4 ] -
muncul. Pada konsentrasi borat tinggi, natrium perborate dengan anion dimer mengkristal keluar, karena kelarutannya relatif rendah.
The soluble monohydrate form is better than tetrahydrate and has higher heat stability; this is prepared by heating the tetrahydrate.
Get started
Sodium perborate is produced by the borax reaction Na
2 B < span>
4 O
7 and sodium hydroxide NaOH to give sodium metaborate NaBO
2 , which is then reacted with hydrogen peroxide to provide a hydrated sodium perborate:
- Na
2 B < span>
4 O
7 2 NaOH -> 4 NaBO
2 H
2 O
- 2 NaBO
2 2 H
2 O
2 -> Na
2 B
2 O
4 (OH)
4
Surfactants can be added to control the size of the crystal.
Usage
Sodium perborate serves as a stable source of active oxygen in many detergents, laundry detergents, cleaning products, and laundry bleach. This is less aggressive bleach than sodium hypochlorite and other chlorine-based bleach, causing less degradation of dyes and textiles. Borate also has some non-oxidative bleaching properties. Sodium perborate releases oxygen quickly at temperatures above 60 ° C. To make it active at lower temperatures (40-60 ° C), it should be mixed with the appropriate activator, usually tetraacetylethylenediamine (TAED).
Sodium perborate is also present in some teeth whitening formulas for root-treated teeth that are not vital. The compound is inserted into the root canal and left in place for a long period of time to allow it to diffuse into the tooth and remove the whitening stain from the inside out. However, this use has been banned in the European Union.
This compound has antiseptic properties and can act as a disinfectant. It is also used as a "vanishing" preservative in some brands of eye drops.
Sodium perborate is also used as an oxidizing reagent in organic synthesis. For example, converting thioeters into sulfoxides and sulfones.
Security
In the EU, sodium perborate, like most borates, is classified as "carcinogenic, mutagenic, or toxic for reproduction" (CMR), category 1B Regulation (EC) 790/2009, as a result of being included in Section 3 of Annex VI of Regulation 1272/2008 on Classification, Labeling and Packaging (CLP) of substances and mixtures. As a result, its use has been automatically banned in cosmetic products in the European Union, in any concentration, from December 1, 2010. It extends to the use of perborates for dry teeth.
See also
- Amosan
- Sodium percarbonate
- Sodium perphosphate
- Places
References
External links
- Borax Detergent Book: Bleaching
- Inventory of National Pollutants - Boron and compounds
- History of sodium perborate, image
- Sodium perborate in organic synthesis
Source of the article : Wikipedia
0 Comments