Cheat sheet · NEET Preparation Chemistry
Haloalkanes and Haloarenes cheat sheet
The whole chapter on one page: key formulas, facts and the points to remember, for quick revision before a test.
NEET · Chemistry
Cheat sheet
Class 12 · Chapter 6Haloalkanes and Haloarenes
SN1: carbocation, racemisation, 3° fastest. SN2: one step, inversion, 1° fastest.
1. Preparation
- Alcohols + HX, PCl₅, SOCl₂ (best: gases escape).
- Alkenes + HX (Markovnikov).
- Finkelstein (NaI/acetone), Swarts (AgF).
- Sandmeyer: diazonium salt + CuX → haloarene.
2. SN1 vs SN2
| Feature | SN1 | SN2 |
|---|---|---|
| Steps | two (carbocation) | one (concerted) |
| Order | first | second |
| Reactivity | 3° > 2° > 1° | 1° > 2° > 3° |
| Stereo | racemisation | inversion (Walden) |
3. Reactions
- Elimination with alc. KOH: Saytzeff (more substituted alkene).
- Wurtz (R–R), Wurtz–Fittig, Fittig.
- Grignard: RX + Mg in dry ether → RMgX.
4. Haloarenes
- Less reactive to nucleophiles (resonance, sp² C).
- –NO₂ at o/p increases reactivity.
- Electrophilic substitution at o/p positions.
5. Key Points
- Chirality: non-superimposable mirror images.
- Freons damage ozone.
- DDT: persistent pesticide.
- Iodoform is an antiseptic.
Remember: Preparation | SN1 vs SN2 | haloarene reactivity
Haloalkanes and Haloarenes: questions and notes
More NEET Preparation Chemistry cheat sheets
- Some Basic Concepts of Chemistry
- Structure of Atom
- Classification of Elements and Periodicity in Properties
- Chemical Bonding and Molecular Structure
- Thermodynamics
- Equilibrium
- Redox Reactions
- Organic Chemistry – Some Basic Principles and Techniques
- Hydrocarbons
- Solutions
- Electrochemistry
- Chemical Kinetics
- The p-Block Elements
- The d- and f-Block Elements
- Coordination Compounds
- Haloalkanes and Haloarenes
- Alcohols, Phenols and Ethers
- Aldehydes, Ketones and Carboxylic Acids
- Amines
- Biomolecules
Practise Haloalkanes and Haloarenes
Sign up free to practise the full chapter. Questions you get wrong come back until you've mastered them.
Start practising freeFree to start · No credit card needed