Question

Amorphous boron of 95% to 98% purity is obtained by :

• A. Heating B2O3 with H2 .
• B. Heating B2O3 with Mg or Na at high temperature.
• C. Heating KBF4 with Na or K.
• D. Heating BBr3 with H2 in presence of a catalyst.

Answer 1

Answer: (B)

Heating B2O3 with Mg or Na at high temperature.

Answer 2

B2O3 + 3Mg or Na $\underset{\Delta}{\overset{\quad Hightemperatur\quad}{\rightarrow}}$2B + 3MgO / Na2O