Question

In which of the following reaction, Boron does not act as reducing agent ?

• A. $B+C{O}_2\to$
• B. $B+Mg\to$
• C. $B+Si{O}_2\to$
• D. $B+HN{O}_3\to$

Answer 1

The correct option is B $B+Mg\to$

Boron does not act as a reducing agent in the reaction

$2B+3Mg\to M{g}_3{B}_2$

In this reaction, Mg is oxidized to $M{g}^{2+}$. Hence, B acts as an oxidising agent. B itself is reduced.

Note: B reduces $Si{O}_2$ to Si and $C{O}_2$ to C.
$4B+3Si{O}_2\to 3Si+2B_2{O}_3$
$4B+3C{O}_2\to 3Si+2B_2{O}_3$