Key Chemistry Formulae from Chapter 4: Amines (NCERT, Class XII)

General Formula for Amines:
- Primary Amines: $RN H_{2}$
- Secondary Amines: $R_{2} N H$
- Tertiary Amines: $R_{3} N$
Nomenclature:
- IUPAC Naming for Amines: $Primary Amine: Alkanamine, e.g., CH_{3} N H_{2} is Methanamine$ $Secondary Amine: N-Alkylalkanamine, e.g., CH_{3} N H C_{2} H_{5} is N-Methylethanamine$

Reduction of Nitro Compounds: $R-NO_{2} + 3 H_{2} Pt / N i R-NH_{2} + 2 H_{2} O$
- Explanation: Reduction of nitro compounds to primary amines using hydrogen gas in the presence of a catalyst (Pt/Ni).
Ammonolysis of Alkyl Halides: $R-X + NH_{3} 373 K R-NH_{2} + H X$
- Explanation: Alkyl halides react with ammonia to form primary amines.
Reduction of Nitriles: $R-C \equiv N + 4 [H] L i A l H_{4} R-CH_{2} NH_{2}$
- Explanation: Reduction of nitriles to primary amines using lithium aluminium hydride.
Gabriel Phthalimide Synthesis: $C_{6} H_{4} (CO)_{2} N^{-} + R - X \to C_{6} H_{4} (CO)_{2} N - R \to R-NH_{2} + Phthalic acid$
- Explanation: Formation of primary amines using phthalimide as a precursor.
Hoffmann Bromamide Degradation: $R-CONH_{2} + B r_{2} + 4 N a O H \to R-NH_{2} + N a_{2} C O_{3} + 2 N a B r + 2 H_{2} O$
- Explanation: Degradation of amides to amines with one less carbon atom using bromine and sodium hydroxide.

Boiling Points of Amines:
- $Primary amine > Secondary amine > Tertiary amine$
- Explanation: Due to the extent of hydrogen bonding, primary amines have the highest boiling points, followed by secondary, then tertiary amines.

Basicity of Amines: $R-NH_{2} + H Cl \to R-NH_{3}^{+} C l^{-}$
- Explanation: Amines act as bases and react with acids to form ammonium salts.
Acylation Reaction: $R-NH_{2} + R^{'} COCl \to R-NHCO-R’ + H Cl$
- Explanation: Amines react with acyl chlorides to form amides.
Carbylamine Reaction: $R-NH_{2} + C H C l_{3} + 3 K O H \to R-NC + 3 K Cl + 3 H_{2} O$
- Explanation: Primary amines react with chloroform and alcoholic potassium hydroxide to form isocyanides.

Stoichiometric Calculation Example:
- Problem: Calculate the amount of aniline required to prepare 2 moles of benzenediazonium chloride.
- Solution: $C_{6} H_{5} N H_{2} + N a N O_{2} + H Cl \to C_{6} H_{5} N_{2}^{+} C l^{-} + N a Cl + 2 H_{2} O$
- - Amount Calculation:
  - - Molar Mass of Aniline: 93 g/mol
    - For 2 moles of benzenediazonium chloride, 186 g of aniline is required.

Incorrect Unit Conversion:
- Mistake: Confusing molar mass with density.
- Strategy: Always check units and conversion factors before finalizing the answer.
Misinterpretation of Reactions:
- Mistake: Misidentifying the product in ammonolysis reactions.
- Strategy: Always double-check reaction conditions and reagents used.

Primary, Secondary, Tertiary Amines: Differ based on the number of hydrogen atoms replaced by alkyl/aryl groups.
Preparation Methods: Includes reduction of nitro compounds, ammonolysis, Gabriel synthesis, and Hoffmann degradation.
Chemical Properties: Amines act as bases, engage in acylation, and participate in the carbylamine reaction.
Physical Properties: Boiling points vary with the degree of hydrogen bonding.

Related NEET Topics:
- Thermodynamics: Connection between enthalpy changes in chemical reactions involving amines.
- Kinetics: Rate of reaction involving amines and factors influencing it.

Derive the expression for the equilibrium constant for the reaction of aniline with HCl to form anilinium chloride.
Predict the major product when aniline is treated with bromine water. Explain the orientation of substitution.
What is the role of Gabriel synthesis in the preparation of primary amines? Why is it not suitable for aromatic amines?
Describe the mechanism of the Hoffmann degradation reaction and its significance in synthetic chemistry.

This structured summary covers the key formulae, principles, derivations, and applications needed for NEET preparation from the chapter on Amines.