Question

When orthoboric acid $(H_{3}BO_{3})$ is heated, the residue left is.

• A. Metaboric acid
• B. Boron
• C. Boric anhydride
• D. Borax

Answer 1

Answer: (C)

Boric anhydride

Answer 2

$2H_{3}BO_{3} \rightarrow B_{2}O_{3} + 3H_{2}O$.