Trisodium pentaborate

Trisodium pentaborate is a salt that can form as a monohydrate with formula Na₃B₅O₈(OH)₂·H₂O, which contains the anion dihydroxydopentaborate [B₅O₈(OH)₂]³⁻.^[1]

Trisodium pentaborate

Identifiers
3D model (JSmol)	Interactive image
InChI InChI=1S/B5H4O10.3Na.H2O/c6-2-10-1-11-5(13-2)14-3(7)12-4(8,9)15-5;;;;/h8-9H,1H2;;;;1H2/q-2;;;; Key: GCZJYHCEEQCBQM-UHFFFAOYSA-N
SMILES [Na].[Na].[Na].O1B([O-])O[B+](O)(O)OB12OB([O-])O[B-]O2.O
Properties
Chemical formula	B5H2Na3O10
Molar mass	285.03 g·mol−1
Appearance	Transparent crystal
Solubility in water	Soluble
Structure
Crystal structure	Orthorhombic
Related compounds
Related compounds	probertite, heidornite, garrelsite
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Its formula may be incorrectly given as Na₃B₅O₈·2H₂O, or as 3Na₂O₅B₂O₃·4H₂O. It may also be called simply sodium pentaborate,^[1] but this name is more properly reserved for the compound with elemental formula Na₂O·5B₂O₃·nH₂O.

Structure

Trisodium pentaborate monohydrate crystallizes as thin plates in the orthorhombic crystal system, with symmetry group Pbca and cell parameters a = 880.4 pm, b = 1837.1 pm, c = 1092.4 pm, formulas per cell Z = 8.^[1]