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

Hint: 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.