Covers the core concepts of nucleophilic substitution reactions, focusing on the SN1 and SN2 mechanisms. Explains how leaving groups, nucleophiles, and solvent polarity influence reaction pathways.
Primary halides react slowest with AgNO₃ via SN₁ . CH₃CH₂CH₂I forms AgI (yellow) slowest among the options.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
An allylic halide has the halogen on a carbon adjacent to a double bond. CH₂=CHCH₂CH₂Cl (4-chloro-1-butene) is allylic.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
CH₂=CHCH₂Cl (allyl chloride) forms a stable allylic carbocation via SN₁ , reacting with AgNO₃ to form AgCl .
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
An allylic halide has the halogen on a carbon adjacent to a double bond. CH₃CH=CHCH₂Cl (4-chloro-2-butene) is allylic.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
SN₁ reactivity increases with carbocation stability. (CH₃)2CHCH₂C(CH₃)2Cl forms a tertiary carbocation, making it most reactive.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
HBr reacts with 2-propanol ( CH₃CHOHCH₃ ) to form 2-bromopropane ( CH₃CHBrCH₃ ) via nucleophilic substitution.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
Thionyl chloride ( SOCl₂ ) reacts with alcohols to form alkyl chlorides, producing SO₂ and HCl , both gases, making it preferred for pure product formation.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
Chlorine adds across the double bond of ethene in a non-polar solvent like CCl₄ , forming 1,2-dichloroethane ( CH₂ClCH₂Cl ).
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
AgNO₃ in ethanol tests SN₁ reactivity. (CH₃)3CBr (tertiary) forms a stable carbocation, reacting fastest.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
CH₃CHClCH₂CH₃ (2-chlorobutane) forms a planar carbocation via SN₁ , leading to a racemic mixture of 2-butanol.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
A vinylic halide has the halogen on a carbon of a C=C bond. CH₃CH=CHBr (1-bromopropene) is vinylic.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
SN₁ reactivity increases with carbocation stability. (CH₃)3CCl (tertiary) forms a stable tertiary carbocation, making it most reactive.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nucleophilic Substitution Reactions - SN1 and SN2 Mechanisms
