Boron oxide (B2O3)

Boron oxide (B2O3);Boric oxide;Boron sesquioxide;Boron trioxide;Fused boric acid;Boric acid (HBO2),anhydride;Boric oxide (B2O3);Boria;Boric anhydride;Diboron trioxide;Boracic anhydride;Boron oxide;Boria (B2O3);Boric acid anhydride;Boron(III) oxide;Boron oxide (BO1.5);B 108406;Boron oxide (B0.67O);12640-42-5;56116-04-2;56145-44-9;56312-91-5;56312-92-6;56312-93-7;56312-94-8;91863-27-3;102967-73-7;144919-64-2;163701-88-0;1858211-82-1;2566446-91-9

1303-86-2

B2O3

JKWMSGQKBLHBQQ-UHFFFAOYSA-N

71.63610

72.01900

215-125-8

0836

DTXSID7034387

Colorless, brittle, vitreous, semitransparent lumps or hard, white crystals|Colorless, glassy or hexagonal crystals, hygroscopic|Colorless powder or vitreous crystals

2810001000

Boron Compounds

43.37000

-1.60300

Boron oxide appears as colorless, semi-transparent glassy lumps or hard white odorless crystals. Mp 450°C; bp: 1860°C. Density: 2.46 g cm-3. Moderately soluble in water. Used as an insecticide; as the starting material for the synthesis of other boron compounds; as a fluxing agent in enamels and glasses; and in mixture with 2-6% boron nitride, as a bonding agent in the hot isostatic pressing of boron nitride ceramics.

2.46 g/cm³

450 °C

1860 °C (approx)

1860ºC

INDEX OF REFRACTION: 1.61

H2O: 36 g/L (25 ºC)

Store in a cool, dry place. Store in a tightly closed container.

0 mmHg (approx)

>1 (vs air)

Noncombustible Solid

Odorless

Slightly bitter taste

pH = 5.1 at 20 °C 1.0% solution

Enthalpy of fusion: 24.56 kJ/mol at 450 °C|Standard enthalpy of formation: -1273.5 kJ/mol (crystal); -843.8 kJ/mol (gas); molar heat capacity at 25 °C: 62.8 J/K mol (crystal); 66.9 J/K mol (gas)|Mohs' hardness: 4; mildly hygroscopic at room temperature; reaction with water is exothermic, -75.94 kJ/mol|Slowly reacts with water to form boric acid|Colorless, vitreous crystals; solubility: in water at 0 °C 1.1 g/100 cu cm, at 100 °C 15.7 g/100 cu cm; sol in acid, alcohol. Index of refraction: 1.485; MP: approx 450 °C; Density: 1.812 at 25 °C at 4 °C /oxide glass/|Heat of vaporization: 390.4 kJ/mol at 1500 K; 431.4 kJ/mol at 298 K; boiling point: 2316 °C (extrapolated); viscosity: 10.60 cP at 350 °C; 4.96 cP at 700 °C; 4.00 at 1000 °C; density: 1.8766 g/mL at 0 °C; 1.844 g/mL at 18-25 °C; 1.81 g/mL at 18-25 °C (well-annealed); 1.648 g/mL at 500 °C (quenched); 1.528 g/mL at 1000 °C (quenched); index of refraction: 1.463 at 14.4 °C; specific heat capacity: 62.969 J/kg K at 298 K; heat of formation: -1252.2 kJ at 298.15 K /Vitreous boric oxide/

No rapid reaction with air No rapid reaction with water

Salts, Acidic

BORON OXIDE is non-combustible. Of generally low chemical reactivity. Reacts exothermically but slowly with water to form boric acid, a weak acid. Reacts exothermically with strong bases. May react with strong reducing agents such as metal hydrides, metal alkyls to generate flammable or explosive gases. May react violently on contact with bromine pentafluoride. Corrosive to metals in the presence of air.

13.50 eV

Noncombustible Solid

Very corrosive to metals in the presence of oxygen