Sodium pentaborate

Not to be confused with Trisodium pentaborate.
Disodium decaborate
Names
Other names
Sodium pentaborate
Identifiers
3D model (JSmol)
ECHA InfoCard 100.031.371 Edit this at Wikidata
EC Number
  • 234-522-7
UNII
  • InChI=1S/B5O8.Na/c6-1-8-3-11-4-9-2(7)10-5(12-3)13-4;/q-1;+1
    Key: OLBJLOUJSZVXOT-UHFFFAOYSA-N
  • B(=O)OB1OB2OB(OB(O2)O1)[O-].[Na+]
Properties
Na+[B5O6(OH)4]− or Na+[B5O7(OH)2]−·H2O
Molar mass 241.06 g·mol−1
Appearance Colorless crystalline solid
Soluble
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Sodium pentaborate, more properly disodium decaborate, is a chemical compound of sodium, boron, and oxygen; a salt with elemental formula NaB5O8, Na2B10O16, or Na2O·5B2O3. It is a colorless crystalline solid, soluble in water.

The compound is often encountered or traded as hydrates NaB5O8·nH2O, Na2B10O16·2nH2O, or Na2O·5B2O3·2nH2O for n = 2,[1] 4,[2][3] 5,[4][5] or other values. This formula is often misleading as some of the water molecules are actually hydroxyl groups covalently attached to boron atoms.

The compound is used in agriculture as a boron supplement in fertilizer with various trade names such as Solubor[5] and Aquabor.[3] It has also been tested as an additive to improve plasma electrolytic oxidation of magnesium alloys.[4]

The name "sodium pentaborate" has also been used for a distinct compound with formula Na3B5O8·nH2O, better called trisodium pentaborate.[6]

  1. ^ Cite error: The named reference mary2008 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference brig2001 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Aquabor was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference seno2022 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Solubor was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference menc1977 was invoked but never defined (see the help page).