Boron - ₅B: reactions of elements

Reaction of boron with air

The behaviour of boron to air depends upon the crystallinity of the sample, temperature, particle size, and purity. By and large, boron does not react with air at room temperature. At higher temperatures, boron does burn to form boron (III) oxide, B₂O₃.

4B + 3O₂(g) → 2B₂O₃(s)

Reaction of boron with water

Boron does not react with water under normal conditions.

Reaction of boron with the halogens

Boron reacts vigorously with the halogens fluorine, F₂, chlorine, Cl₂, bromine, Br₂ to to form the trihalides boron(III) fluoride, BF₃, boron(III) chloride, BCl₃, and boron(III) bromide, BBr₃ respectively.

2B(s) + 3F₂(g) → 2BF₃(g)

2B(s) + 3Cl₂(g) → 2BCl₃(g)

2B(s) + 3Br₂(g) → 2BF₃(l)

Reaction of boron with acids

Crystalline boron does not react with boiling hydrochloric acid, HCl, or boiling hydrofluoric acid, HF. Powdered boron oxidizes slowly when treated with concentrated nitric acid, HNO₃.

Reaction of boron with bases