Explore the characteristics of the carbon-halogen bond and the common methods used to prepare haloalkanes. Includes practice problems and explanations for chemistry exams.
NaSH substitutes I in CH₃CH₂I via SN₂ , forming CH₃CH₂SH (ethanethiol).
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
SOCl₂ converts 3-pentanol ( CH₃CH₂CHOHCH₂CH₃ ) to 3-chloropentane ( CH₃CH₂CHClCH₂CH₃ ) via substitution.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
In CH₃CH₂CHClCH₂CH₃ , the Cl-bearing carbon (C₃) is bonded to C₂, Cl, C₄, and one H, so it has 1 hydrogen.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
Bond strength decreases as halogen size increases due to weaker overlap: CH₃F > CH₃Cl > CH₃Br > CH₃I .
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
Bond length increases with the size of the halogen. Among F, Cl, Br, and I, iodine is the largest, so CH₃-I has the longest C-X bond.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
KNO₂ substitutes Cl via SN₂ , forming CH₃CH₂CH₂ONO (propyl nitrite), as NO₂⁻ bonds through oxygen.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
Bond length decreases with smaller halogen size. CH₃F has the shortest C-X bond due to fluorine's small atomic radius.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
SOCl₂ reacts with 1-butanol ( CH₃CH₂CH₂CH₂OH ) to form 1-chlorobutane ( CH₃CH₂CH₂CH₂Cl ), producing SO₂ and HCl gases.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
SN₂ substitution with NaOH favors primary halides. CH₃CH₂I (iodide) reacts fastest due to the best leaving group.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
PCl₅ converts 2-pentanol ( CH₃CH₂CH₂CHOHCH₃ ) to 2-chloropentane ( CH₃CH₂CH₂CHClCH₃ ) via substitution.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
KCN substitutes Br in CH₃CH₂CH₂Br via SN₂ , forming CH₃CH₂CH₂CN (butanenitrile).
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
PBr₃ converts 1-butanol ( CH₃CH₂CH₂CH₂OH ) to 1-bromobutane ( CH₃CH₂CH₂CH₂Br ) by replacing OH with Br.
Ref: NCERT Class 12 Chemistry > Chapter 6: Haloalkanes and Haloarenes > Topic: Nature of C-X Bond and Methods of Preparation
