Subjective Type

Give the diazotisation reaction of aniline. Also give the chemical reaction involved in the preparation of red azo dye and light yellow azo dye.

Solution

The nitrosation of primary aromatic amines with nitrous acid (generated in situ from sodium nitrite and a strong acid, such as hydrochloric acid, sulfuric acid, or $$HBF_4$$) leads to diazonium salts.
Diazonium salts are important intermediates for the preparation of halides (Sandmeyer Reaction, Schiemann Reaction), and azo compounds.
Red Azo dye:
The naphthalen-2-ol ($$\beta$$-naphthol) is dissolved in sodium hydroxide solution and is cooled and mixed with the diazonium chloride solution.
An intense orange-red precipitate is formed.
Yellow azo dye:
The aniline is mixed with the diazonium chloride solution. An yellow colored precipitate is formed.

SIMILAR QUESTIONS

Alcohols, Phenols and Ethers

The total number of $$\sigma$$ and $$\pi$$ bonds present in azobenzene are:

Alcohols, Phenols and Ethers

Complete the following with appropriate structure: $$\displaystyle 2,3-\text{dinitroaniline}\xrightarrow [ (ii)Anisole ]{ (i){ NaNO }_{ 2 }\ and\ HCl\ at\ { 5 }^{ o }C } (A)$$

Alcohols, Phenols and Ethers

Diazo-coupling is use ful to prepare some

Alcohols, Phenols and Ethers

Coupling of benzene diazonium chloride with 1-napthol in alkaline medium will give:

Alcohols, Phenols and Ethers

Benzene diazonium chloride on reaction with aniline in the presence of dilute hydrochloric acid gives:

Alcohols, Phenols and Ethers

Which of the following reagents would not be a good choice for reducing an aryl nitro compound to an amine?

Alcohols, Phenols and Ethers

A compound $$X$$ has molecular formula $${C}_{7}{H}_{7}NO$$. On treatment with $${Br}_{2}$$ and $$KOH$$, $$X$$ gives an amine $$Y$$. The later gives carbylamine test. $$Y$$ upon diazotisation and coupling with phenol gives an azo dye. Thus, $$X$$ is :

Alcohols, Phenols and Ethers

Which statements are correct?

Alcohols, Phenols and Ethers

Complete the following.

Alcohols, Phenols and Ethers

Write short notes on Diazotisation

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