| Reactions of Boron |
Reactions with water |
| Boron will not react with water under normal conditions. |
Reactions with air |
| At higher temperatures, boron does burn in air to form boron(III) oxide, B2O3. |
4B + 3O2(g) 2B2O3(s) |
Reactions with halogens |
| Boron reacts vigorously with fluorine, chlorine, and bromine to form boron(III) trihalides. |
2B(s) + 3F2(g) 2BF3(g) |
2B(s) + 3Cl2(g) 2BCl3(g) |
2B(s) + 3Br2(g) 2BBr3(g) |
Reactions 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. |
| Reduction Potentials | |
| Balanced half-reaction | E0 / V |
H3BO3 + 3H+ + 3e- B(s) + 3H2O
|
-0.869 |
H2BO3- + 4H+ + 3e- B(s) + 3H2O
|
-0.687 |
HBO32- + 5H+ + 3e- B(s) + 3H2O
|
-0.437 |
BO33- + 6H+ + 3e- B(s) + 3H2O
|
-0.165 |
B(OH)3 + 3H+ + 3e- B(s) + 3H2O
|
0.87 |
BF4- + 3e- B(s) + 4F- |
-1.04 |
H2B4O7 + 12H+ + 12e- 4B(s) + 7H2O
|
-0.836 |
B4O72- + 14H+ + 12e- 4B(s) + 7H2O
|
-0.792 |