Amines

Step 1: Recall effect of alkyl groups.
Alkyl groups release electrons by +I effect, increasing electron density on N and hence its basicity.
Step 2: Compare.
- (A) Aniline (C H NH ): Lone pair delocalized into ring, basicity decreases.
- (B) Dimethylamine: Strong +I effect, lone pair available, very basic.
- (C) Trimethylamine: Steric hindrance reduces basicity in aqueous solution.
- (D) Ammonia: Less basic than substituted alkyl amines.
Step 3: Conclusion.
Most basic among them is (CH ) NH.

Step 1: Recall Hinsberg test.
The Hinsberg test distinguishes between primary, secondary, and tertiary amines. The reagent used is p-toluene sulphonyl chloride (TsCl).
Step 2: Explanation.
- Primary amines form soluble sulphonamides.
- Secondary amines form insoluble sulphonamides.
- Tertiary amines do not react.
Step 3: Conclusion.
Thus, Hinsberg reagent is p-toluene sulphonyl chloride.

Step 1: Recall the reaction.
Acetamide reacts with Br /KOH in the Hofmann bromamide reaction.
Step 2: Reaction details.
R–CONH R–NH + CO .
Here, CH CONH → CH NH .
Step 3: Conclusion.
The product is methyl amine.

Step 1: Principle.
In aqueous solution, basicity of amines depends on the electron-releasing (+I) effect of alkyl groups \emph{and} solvation. General order:
because secondary amines have strong +I effect and still good solvation; tertiary amines suffer from steric hindrance and poorer solvation.
Step 2: Apply to given amines.
Least basic most basic: Step 3: Check.
This follows the aqueous-phase basicity trend: 2°>1°>3°>NH .

Step 1: Understand the structure of amines.
Amines are organic compounds that contain nitrogen (N) attached to carbon atoms. The general formula for primary amines is C H N, where "n" is the number of carbon atoms in the molecule.
Step 2: Analyze the options.
- C H N (Option A) is the correct formula for primary amines. - C H N (Option B) would suggest an additional hydrogen, which is not typical for amines. - C H N (Option C) is incorrect for primary amines. - C H N (Option D) is also incorrect as it does not account for the extra hydrogen in primary amines.
Step 3: Apply to the options.
The correct formula for primary amines is (A) C H N.
Final Answer:

Step 1: Understand Hinsberg's reagent.
Hinsberg's reagent is benzene sulphonyl chloride (C H SO Cl). It is used in the Hinsberg test for the identification of amines.
Step 2: Analyze the options.
- Benzene sulphonyl chloride (Option A) is the correct answer as it is the Hinsberg reagent used for testing amines. - Benzene sulphonic acid (Option B) is a different compound used in other reactions. - Ethyl oxalate (Option C) is not involved in the Hinsberg test. - Acetyl chloride (Option D) is used in the preparation of acyl derivatives but not in the Hinsberg test.
Step 3: Apply to the options.
The correct answer is (A) Benzene sulphonyl chloride.
Final Answer:

Step 1: Define linkage isomerism.
Linkage isomerism occurs when a ligand can bind to the metal center in more than one way. This typically happens with ligands that have more than one donor atom, such as NO , SCN , and CN .
Step 2: Analyze the options.
- NO can bind through the nitrogen atom or the oxygen atom, so it can exhibit linkage isomerism. - SCN can bind through either the sulfur or nitrogen atom, so it can also show linkage isomerism. - CN can bind through the carbon atom or the nitrogen atom, so it can show linkage isomerism. - NH , however, only binds through the nitrogen atom and does not show linkage isomerism.
Step 3: Apply to the options.
Since NH cannot show linkage isomerism, the correct answer is (D).
Final Answer: