Question

A compound $X$ of boron reacts with $N{H_3}$ on heating to give another compound $Y$ which is called inorganic benzene. The compound $X$ can be prepared by treating $B{F_3}$ with lithium aluminium hydride. The compound $X$ and $Y$ are represented by formula:
(A) ${B_2}{H_6},{B_3}{N_3}{H_6}$
(B) ${B_2}{O_3},{B_3}{N_3}{H_6}$
(C) $B{F_3},{B_3}{N_3}{H_6}$
(D) ${B_3}{N_3}{H_6},{B_2}{H_6}$

Answer 1

Lithium aluminium hydride is a strong reducing agent having formula $LiAl{H_4}$ and also known as LAH. Lithium aluminium hydride as having a strong reducing agent can reduce almost all the ketones into alcohol.

Complete step-by-step answer
First we start with the reaction,
$X + N{H_3} \to Y$
Now, we have to know what inorganic benzene is.
Inorganic benzene: Inorganic benzene is an inorganic compound also known as Borazine having formula ${B_3}{N_3}{H_6}$ .
As given is a compound of boron and is inorganic benzene.
Now, we have to know any reaction in which the formation of borazine with ammonia,
So, the reaction which forms borazine with ammonia,
$3{B_2}{H_6} + 6N{H_3} \to 2{B_3}{N_3}{H_6}$
So, the $X$ is ${B_2}{H_6}$ and the $Y$ is ${B_3}{N_3}{H_6}$ .
Also for confirmation the $X$ is correct or not, we can use another given reaction.
We have to know the reaction of $B{F_3}$ with lithium aluminium hydride,
So, the reaction of $B{F_3}$ with lithium aluminium hydride as follows:
$4B{F_3} + LiAl{H_4} \to 2{B_2}{H_6} + 3LiF + 3Al{F_3}$
So, in these reaction only one compound of the boron that is ${B_2}{H_6}$
So, from here we confirm that the $X$ is ${B_2}{H_6}$ also known as Diborane.
Hence, $X$ is ${B_2}{H_6}$ which is diborane and the $Y$ is ${B_3}{N_3}{H_6}$ which is borazine (Inorganic Benzene).

Hence, the correct option is (A) ${B_2}{H_6},{B_3}{N_3}{H_6}$.

Additional information:
Diborane is having two types of bonds, one is covalent bond and another one is three-centre two electron bond and it is also a Lewis acid. It is most commonly used for the reduction of carboxylic acids.

Note:
Inorganic benzene is also known as Borazine or borazole which is having a formula ${B_3}{N_3}{H_6}$ . It is a cyclic compound. The compound has the same structure and isoelectric with the benzene and having an inorganic compound named as inorganic benzene. Also, the borazine is more reactive than benzene.