Question

${B_2}{H_6}$ reacts with ${O_2}$ and ${H_2}O$ respectively to form:
A. ${B_2}{O_3},{H_3}B{O_3}$
B. ${B_2}{O_3},B{H^ - }_4$
C. $HB{O_2},{H_3}B{O_3}$
D. ${H_3}B{O_3},HB{O_2}$

Answer 1

Hint: We know that ${B_2}{H_6}$ is called diborane. It is a colourless compound containing boron and hydrogen. It is a gas with sweet odour, also known as boron hydride and diborane hexahydride. The complete combustion of diborane is strongly exothermic. It is used as a catalyst for hydrocarbon polymerisation, rubber vulcaniser and as a flame-speed accelerator.
${B_2}{H_6}$ reacts with ${O_2}$ and ${H_2}O$ respectively to form boric anhydride and boric acid. The reactions are as follows;
$\begin{gathered} {B_2}{H_6} + {H_2}O \to 2{H_3}B{O_3} + 3{H_2} \\\ {B_2}{H_6} + 3{O_2} \to {B_2}{O_3} + 3{H_2}O \\\ \end{gathered}$
Hence boric anhydride $({B_2}{O_3})$ and boric acid $({H_3}B{O_3})$ is formed by the reaction of diborane with oxygen and water respectively.

So option A is the correct answer to this problem.

Additional information- Boric anhydride or diboron trioxide $({B_2}{O_3})$ acts as an insecticide of the starting material for the synthesis of other boron compounds. It is also used as a fluxing agent in enamels and glasses. It acts as an acid catalyst in organic synthesis reactions. Boric acid $({H_3}B{O_3})$ is used in prevention of athlete’s foot. It acts as an antibacterial compound. It used to kill cockroaches, ants, silverfish, fleas , beetles and other pesticides at home. Boric acid can also be used as a cleanser, stain-remover and odour remover from clothes. It is a natural antiseptic and astringent. A teaspoon of boric acid in distilled water makes a good wash for wounds.

Note : Diborane is a highly reactive and versatile substance which has numerous applications. Hence we come to know that diborane reacts exothermically with oxygen to form boron trioxide and water. It reacts violently with water and produces hydrogen and boric acid.