A compound $(A)$ of boron reacts with $N M e_{3}$ to give an adduct $(B)$ which on hydrolysis gives a compound $(C)$ and hydrogen gas. Compound $(C)$ is an acid. Identify the compounds $A, B$ and $C$ . Give the reactions involved.

Open in App

Solution

As per the question,

$A + N M e_{3} \to B$

$B$ is an adduct.

On hydrolysis,

$B + H_{2} O \to C + H_{2} (g)$

Also stated that $C$ is acidic in nature.

$Formation of adduct$

Diborane undergoes cleavage reactions with Lewis bases such as Trimethyl nitrogen $N (M e)_{3}$ to give borane adducts, $B H_{3} \cdot N M e_{3}$

It is an addition compound of borane and Lewis base.

$B_{2} H_{6} + 2 N M e_{3} \to 2 B H_{3} \cdot N M e_{3}$

Therefore, $A$ is diborane $(B_{2} H_{6})$ .

$B$ is adduct or addition compound called borane adduct i.e. $B H_{2} \cdot N M e_{3}$

$Adduct to acid conversion$

Compound $B$ on hydrolysis gives boric acid, $H_{3} B O_{3}$

The reaction is:

$B H_{3} \cdot N M e_{3} + 3 H_{2} O \to H_{3} B O_{3} + N M e_{3} + 3 H_{2}$

Therefore, the compound $C$ is orthoboric acid $(H_{3} B O_{3})$ which is not a protonic acid but acts as a Lewis acid.

Suggest Corrections

Similar questions

A compound

A

of boron reacts with

N M e_{3}

to give an adduct

B

which on hydrolysis gives a compound

C

and a gas

D

. Compound

C

is an acid.

Compound

C

is :

Q. an organic compound (A) reacts with ethanol to give (B) and (C). on hydrolysis (c) gives (B) and (D). oxidation of (d) gives (B). B is an acid and forms a salt with Ca(OH)2 which on dry distillation gives E, C3H6O. identify the compounds At to E and write all reactions involved

Q. An monovalent metal A gives a compound B (molecular mass = 40) on reacting with water. The compound B gives a soluble compound C on treatment with aluminium oxide. Identify A, B and C and give the reaction involved.

Q. An alkali metal A gives a compound B (molecular mass = 40) on reacting with water. The compound B gives a soluble compound C on treatment with aluminium oxide. Identify A, B and C and give the reaction involved.

Question 53
An element A reacts with water to form a compound B which is used in whitewashing. The compound B on heating forms an oxide C which on treatment with water gives back B. Identify A, B and C and give the reactions involved.

Join BYJU'S Learning Program

A compound (A) of boron reacts with NMe3 to give an adduct (B) which on hydrolysis gives a compound (C) and hydrogen gas. Compound (C) is an acid. Identify the compounds A,B and C. Give the reactions involved.

A compound $(A)$ of boron reacts with $N M e_{3}$ to give an adduct $(B)$ which on hydrolysis gives a compound $(C)$ and hydrogen gas. Compound $(C)$ is an acid. Identify the compounds $A, B$ and $C$ . Give the reactions involved.