BORON - B

Properties of Boron:

Nonmetal. Gray-black (crystal) or brown (amorphous). Refractory, very hard, brittle. Chemically passive. Does not react with hydrogen, water, diluted acids, diluted alkalis into the solution. Reacts with water steam, concentrated nitric acid, halogen, nitrogen, hydrogen fluoride and hydrogen sulfide, ammonia and alkalis when heated.


Molar mass g/mol 10.811
Density g/cm3 2.340
Melting point °C 2075
Boiling point °C 3700

Methods for preparation of Boron:

B2H6 = 2B + 3H2 (300-500°C)

B2O3 + 2Al = Al2O3 + 2B (800-900°C)

2BCl3 + 3H2 = 2B + 6HCl (800-1200°C)

2BI3 = 2B + 3I2 (over 700°C or on light)


Сhemical reactions with Boron:

2B + 3H2O(steam) = B2O3 + 3H2 (700-800°C).

B + 3HNO3(hot, conc.) = B(OH)3↓ + 3NO2↑.

2B(amorphous) + 2NaOH(conc.) + 6H2O = 2Na[B(OH)4] + 3H2↑.

4B + 4NaOH + 3O2 = 4NaBO2 + 2H2O (350-400°C).

4B + 3O2 = 2B2O3 (700°C, burning on air).

2E + 3E2 = 2BE3 (30°C, E = F; over 400°C E = Cl, Br, I).

2B + 3S = B2S3 (over 600°C).

2B + N2 = 2BN (900-1000°C).

B + P(red) = BP (900-1200°C).

4B + C(graphite) = B4C (over 2000°C, impurity B13C2).

2B + 6HE = BE3 + 3H2 (400-500°C; E = F, Cl).

2B + H2S = B2S3 + 3H2 (800-900°C).

2B + 2NH3 = 2BN + 3H2 (1000-1200°C).

5B + 3NO = B2O3 + 3BN (800°C).

2B + 3CO = B2O3 + 3C(graphite) (1400°C).

4B + 3CS2 = 2B2S3 + 3C(graphite) (930°C).

4B + 3SiO2 = 2B2O3 + 3Si (1300-1500°C).


 

Did you know?

Noble gasses are very unreactive elements and complete outer energy levels.