Home
Class 12
CHEMISTRY
A colourless liquid A(b.p. 184^(@)C) is ...

A colourless liquid `A(b.p. 184^(@)C)` is sparingly soluble in warm water to which it gives feebly alkaline. On treating with `NaNO_(2)` and dil `HCl` in the cold solution, it yields a solution which reacts with an alkaline solution of `beta`-naphthol to give an orange yellow precipitate. Compound A is -

A

`C_(6)H_(5)N_(2)Cl`

B

`C_(6)H_(5)NHNH_(2)`

C

`n - C_94)H_(9)NH_(2)`

D

`C_(6)H_(5)NH_(2)`

Text Solution

AI Generated Solution

The correct Answer is:
To determine the identity of compound A, we can follow these steps: ### Step 1: Analyze the properties of compound A - Given that compound A is a colorless liquid with a boiling point of 184°C and is sparingly soluble in warm water, we can infer that it is likely an organic compound. The feebly alkaline nature suggests that it may contain an amine functional group. **Hint:** Look for organic compounds that are colorless liquids with a boiling point around 184°C and have amine characteristics. ### Step 2: Consider the reaction with NaNO2 and dilute HCl - The reaction of compound A with sodium nitrite (NaNO2) and dilute hydrochloric acid (HCl) indicates that it is likely an aromatic amine. This reaction typically leads to the formation of a diazonium salt. **Hint:** Recall that aromatic amines react with NaNO2 and HCl to form diazonium salts. ### Step 3: Identify the diazonium salt formed - When aniline (C6H5NH2) reacts with NaNO2 and HCl, it forms benzene diazonium chloride (C6H5N2Cl). This is a key intermediate in many organic reactions. **Hint:** Consider the structure of aniline and how it transforms into a diazonium salt upon treatment with nitrous acid. ### Step 4: Reaction with beta-naphthol - The formed diazonium salt can react with beta-naphthol (C10H7OH) in an alkaline medium to produce an orange-yellow precipitate, which is a characteristic azo dye. **Hint:** Remember that diazonium salts can couple with phenolic compounds to form azo dyes, which are often brightly colored. ### Step 5: Conclusion - Since the properties and reactions align with those of aniline, we conclude that compound A is aniline (C6H5NH2). **Final Answer:** Compound A is aniline (C6H5NH2).
Promotional Banner

Similar Questions

Explore conceptually related problems

Amongst the compounds given, the one that would form a brilliant colored dye on treatment with NaNO_2 in dil. HCl followed by addition to an alkaline solution of beta- naphthol is

Which of the following pair(s) contain species, which react with each other on mixing their aquouos solutions to give yellow precipitate?

NAME: A gas which dissolves in water to give alkaline solution .

Which one of the following compounds on reaction with Na_(2)O_(3) in alkaline medium gives yellow colour solution?

Which of the following compounds will give butanone on oxidation with alkaline KMnO_(4) solution ?

Which of the following compound will give butanone on oxidation with alkaline KMnO_(4) solution ?

Which of the following compound will give butanone on oxidation with alkaline KMnO_(4) solution ?

A solution of a metal ion when treated with KI gives a red precipitate which dissolves in excess KI to give a colourless solution.Moreover, the solution of metal ion on treatment with a solution of cobalt (II) thiocyanate gives rise to a deep blue crystalline precipitate.The metal ion is: