Haloalkanes and Haloarenes – Class 12 Chemistry Notes
📘 Introduction: Haloalkanes and Haloarenes are organic compounds containing halogen atoms attached to alkyl or aryl groups. --- 🔬 Classification: 🧪 Based on Number of Halogen Atoms: Mono, Di, Tri, Poly halogen compounds 🧪 Based on Type of Carbon Chain: Alkyl halides (R–X) Aryl halides (Ar–X) --- 🧪 Nomenclature: IUPAC name: Prefix (halo) + parent hydrocarbon Example: CH₃Cl → Chloromethane C₂H₅Br → Bromoethane --- ⚗️ Preparation of Haloalkanes: 1. From Alcohols: ROH + HX → R–X + H₂O (Using ZnCl₂ as catalyst) 2. From Alkanes (by halogenation): RH + X₂ → R–X + HX (in sunlight) 3. From Alkenes (Addition Reaction): CH₂=CH₂ + HX → CH₃–CH₂X --- 🧪 Physical Properties: Colorless liquids or solids Denser than water Insoluble in water but soluble in organic solvents Boiling point increases with molar mass --- ⚙️ Chemical Reactions: 1. Nucleophilic Substitution (SN1 & SN2): SN1: 2° & 3° haloalkanes (carbocation intermediate) SN2: 1° haloalkanes (one-step reaction) 2. Elimination ...