Helo, reders welcome to “textilesgreen.in“. i am going to explain about benzene diazonium chloride, preparation, reaction and more.

if you want to know about in details. then read complete article.

I have made this guide to help you out.

So, hold your seat and be with the end of guide.

So, you could get valuable information out of it.

Lets get started.

What is benzene diazonium chloride?

It is an organic compound.

It is properly soluble in water.

Formula of this compund is [C6H5N2]Cl.

The chemical structure of this compound is,

diazonium salt
Diazonium salt

you know that what is mean by Diazonium salt.

Diazotwo Nitrogen – N2

and nium mean – + charge and add + salt

Diazo + nium + salt = diazonium salt

You can write, Diazonium salt.

You can write in other form of Diazonium salt is,

R – N2+ (positive) + ions (X negative)

Where, ions may be (Cl negative), Br negative or HSO4 negative etc.

You can write;

R – N+ (positive) triple bond N Cl (negative)

Were, R- is alkyl or aryl

It is alkyl diazonium chloride

benzene diazonium chloride is very useful and very important organic compound.

It is use for preparation of many other important compound. Such as benzene, phenol etc.

It is produced verity of organic compound such as, benzene, phenol, nitrobenzene etc.

It is windly use in organic chemistry.

It is colourless crystal or colourless solid.

Why benzene diazonium chloride is not stored?

It is not stored because it is stable in very short time. In other words it is instability so it is not stored. It is immediately used after preparation because stability is in short time other wise it reacts fast.

benzene diazonium chloride preparation

(Chemical reaction method)

In this reaction, you need aniline (NH2) on Benzene ring and add NaNO2 +HCl then it give benzene diazonium chloride as a product.

When aniline is react with sodium nitrate NaNO2 and (hydrochloric acid) HCl then, it give (Diazonium salt) as a product.

benzene diazonium chloride
Diazonium salt preparation

After reaction you can see First N2 is removed and sodium chloride (Nacl) is removed.

In this reaction, Na + Cl attached together and it form Nacl, it is called sodium chloride. and then water molecule is formed. In other words, two atoms of hydrogen and one atom of oxygen is attached together then it form water molecule, for example;

H2 + O = H20 (water molecule)

where H is Hydrogen and O is oxygen.

Mechanism behind this reaction.

First off all I m talking about , how to react NaNO2 and HCl each other.

You know that NaNO2 is also write in other form as shown in figure.

If sodium nitrate is react with hydrochloric acid then it give HNO2 + NaCl sodium chloride as shown in figure.

NaNO2 + HCl – HNO2 + NaCl

Where, NaNO2 – sodium nitrate

HCl – hydrochloric acid

After reaction HNO2 or NaCl is formed.


HNO2 – H – O – N = O

O – oxygen, H – Hydrogen, N – Nitrogen

It is lone pair of the atoms.

You can see oxygen atoms is attack on HCl and a product is formed as shown in figure.

benzene diazonium chloride

this product is again react with hydrochloric acid HCl then oxygen is again attack on HCl then it give water molecule and nitrosonium ion as shown in second figure.

benzene diazonium chloride mechanism

Preparation (Laboratory method)

Second method

if you follow properly according to this flow chart it is easy to produce diazonium salt in laboratory.

benzene diazonium chloride preparation

Benzene diazonium chloride is very useful compound because it is produce different types of organic compound and it is windly use in organic chemistry. So, I m going to explain in details about different reaction. Lets get started.

  1. Benzene diazonium chloride to benzene?

When Benzene diazonium chloride is treated with the presence of atmosphere for water then it give phenol product and N2 or hydrochloric acid (HCl) will remove as shown in figure.

benzene diazonium chloride to phenol
Phenol product is formed

In this reaction, first N2 will remove and chlorine Cl + H hydrogen is attached together and form hydrochloric acid (HCl).

After finally one hydrogen and one oxygen joined on Benzene ring and it make phenol.

C6H6+OH were as, O is oxygen and in this reaction H is Hydrogen, it mean,

One atoms of oxygen and one atom of hydrogen. If this to atom joined together on Benzene ring then it made phenol. and it called phenol product.

2. Benzene diazonium chloride to benzene.

When benzene diazonium chloride is treated with the presence of SnCl2 and sodium hydroxide (NaOH), it form Benzene product. HCl and N2 will removed as shown on figure.

benzene diazonium chloride to benzene
Benzene as a product is formed

3. Benzene Diazonium Chloride + KI

When Diazonium salt is react with the presence of potassium iodide (KI) then it give ido benzene and N2 and KCl is formed.

Read more


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