Amines

Acid anhydride (e.g., (RCO) O) reacts with a primary amine (RNH ) to form an amide (RCONHR) and a carboxylic acid. The functional group in the primary product is the amide group.
Answer: amide.

i. Acetic Acid to Acetic Anhydride:
P O dehydrates two acetic acid molecules.
ii. Acetic Acid to Ethyl Alcohol:
LiAlH reduces the carboxyl group to a primary alcohol.
Methylphenylamine:
IUPAC Name: N-Methylaniline.
Structure: .

i. Chloroform and Caustic Potash: Ethyl amine ( ) undergoes the carbylamine reaction: Product: Ethyl isocyanide (foul-smelling).
ii. Nitrous Acid: Ethyl amine reacts with HNO (from NaNO + HCl) to form an alcohol via diazonium ion decomposition: Product: Ethanol.

Step 1: Understanding the Concept:
The basicity of amines depends on the availability of the lone pair of electrons on the Nitrogen atom.
Factors affecting basicity include:
1. Inductive effect (+I effect of alkyl groups increases electron density).
2. Solvation effect (hydrogen bonding with water stabilizes the cation).
3. Steric hindrance (bulky groups hinder the approach of protons).
Step 2: Detailed Explanation:
In the gas phase, the order is strictly .
However, in aqueous solution, the interplay of the +I effect and solvation/steric factors makes the secondary ( ) amine the most basic.
For Methyl groups ( ):
For Ethyl groups ( ):
In general, ammonia ( ) is always the least basic because it lacks the +I effect of alkyl groups. The secondary amine ( ) is generally the most basic.
Option (d) correctly places at the bottom and as greater than and .
Step 3: Final Answer:
The order is .

Step 1: Understanding the Concept:
1. Sulfanilic acid contains both acidic ( ) and basic ( ) groups, leading to internal salt formation.
2. Coupling reactions of diazonium salts occur with activated aromatic rings.
Step 2: Detailed Explanation:
Zwitter ion of Sulfanilic acid:
The proton from the sulfonic group is transferred to the amino group.
Structure:

Coupling with Phenol:
Benzene diazonium chloride reacts with phenol in a weakly alkaline medium ( 9-10) at low temperature (273-278 K). The diazonium cation attacks the para-position of the phenoxide ion.
Reaction:

The product is p-hydroxyazobenzene, an orange-colored dye.
Step 3: Final Answer:
The zwitter ion is . The phenol coupling produces an orange azo dye.

Step 1: Understanding the Concept:
The conversion involves reducing an amide group ( ) to a primary amine group ( ) while retaining the number of carbon atoms.
Step 2: Detailed Explanation: Acetamide ( ) has two carbon atoms. Ethyl amine ( ) also has two carbon atoms.
Strong reducing agents like Lithium Aluminium Hydride ( ) are used for this purpose.
Reaction:

Step 3: Final Answer:
Acetamide is converted to ethyl amine by reduction with in the presence of dry ether.