Haloalkanes and Haloarenes – MCQs
Q1. The functional group of haloalkanes is:
A. –OH
B. –X (halogen)
C. –COOH
D. –NH₂
Q2. The IUPAC name of CH₃CH₂CH₂Cl is:
A. 1-Chloropropane
B. 2-Chloropropane
C. Propyl chloride
D. Isopropyl chloride
Q3. Which of the following is a tertiary haloalkane?
A. CH₃CH₂CH₂Cl
B. (CH₃)₃CCl
C. CH₃CHClCH₃
D. CH₃CH₂CH₂Br
Q4. Haloarenes differ from haloalkanes because:
A. Halogen is bonded to sp³ carbon
B. Halogen is bonded to sp² carbon of benzene
C. They are more reactive to SN2
D. They are always primary
Q5. Which of the following is an aryl halide?
A. C₆H₅Cl
B. CH₃CH₂Cl
C. CH₃CH₂CH₂Cl
D. CH₃CCl₃
Q6. Which reaction is used to prepare alkyl halides from alcohols?
A. SN1 substitution
B. Halogenation with PCl₅ or SOCl₂
C. Free radical halogenation
D. Friedel-Crafts alkylation
Q7. The main mechanism for tertiary haloalkanes in aqueous solution is:
A. SN1
B. SN2
C. E2
D. Free radical
Q8. The main mechanism for primary haloalkanes in aqueous solution is:
A. SN1
B. SN2
C. E1
D. Electrophilic substitution
Q9. Chlorobenzene reacts with NaOH under harsh conditions to give:
A. Phenol
B. Aniline
C. Benzene
D. Nitrobenzene
Q10. Which of the following halides undergoes Wurtz reaction?
A. Primary alkyl halides
B. Tertiary alkyl halides
C. Aryl halides
D. Benzyl halides
Q11. The order of reactivity of haloalkanes towards SN2 reaction is:
A. Primary > Secondary > Tertiary
B. Tertiary > Secondary > Primary
C. Secondary > Primary > Tertiary
D. All equal
Q12. The order of reactivity of haloalkanes towards SN1 reaction is:
A. Tertiary > Secondary > Primary
B. Primary > Secondary > Tertiary
C. Secondary > Primary > Tertiary
D. All equal
Q13. In the reaction CH₃CH₂Cl + KOH → CH₃CH₂OH, KOH acts as:
A. Nucleophile
B. Electrophile
C. Base
D. Radical
Q14. Chlorination of methane in presence of UV light proceeds by:
A. SN1
B. SN2
C. Free radical mechanism
D. Electrophilic substitution
Q15. The product of CH₃CHClCH₃ + KOH (alcoholic) is:
A. CH₃CH=CH₂
B. CH₃CH₂CH₃
C. CH₃CHOHCH₃
D. CH₂ClCH₂CH₃
Q16. Sandmeyer reaction is used to prepare:
A. Aryl halides from aryl diazonium salts
B. Alkyl halides from alcohols
C. Haloalkanes from alkenes
D. Alcohols from alkyl halides
Q17. The halogen in haloarenes is:
A. Easily replaced by nucleophiles
B. Poorly reactive due to resonance
C. Highly reactive to SN2
D. Only reactive in free radical reactions
Q18. Nitrobenzene is prepared by:
A. Nitration of benzene
B. Halogenation
C. Substitution of bromobenzene
D. Free radical halogenation
Q19. The reactivity of haloarenes in nucleophilic substitution is:
A. Higher than haloalkanes
B. Lower than haloalkanes
C. Same as haloalkanes
D. Zero
Q20. Benzyl chloride reacts with aqueous KOH to give:
A. Benzyl alcohol
B. Phenol
C. Chlorobenzene
D. Toluene
Q21. The reaction of CH₃CH₂Br with Mg in dry ether gives:
A. Grignard reagent (CH₃CH₂MgBr)
B. Alcohol
C. Alkene
D. Alkane
Q22. The halogen in tertiary haloalkanes:
A. Is more easily substituted via SN1
B. Is more easily substituted via SN2
C. Reacts only via elimination
D. Does not react
Q23. The order of reactivity for free radical halogenation of alkyl halides is:
A. Tertiary > Secondary > Primary
B. Primary > Secondary > Tertiary
C. Secondary > Tertiary > Primary
D. Equal
Q24. The main product of C₆H₅CH₂Cl + NaOH (aqueous) is:
A. Benzyl alcohol
B. Phenol
C. Chlorobenzene
D. Toluene
Q25. Reaction of chlorobenzene with NaNH₂ gives:
A. Aniline
B. Benzene
C. Nitrobenzene
D. Benzoic acid
Q26. The C–X bond in haloalkanes is:
A. Polar covalent
B. Ionic
C. Non-polar covalent
D. Metallic
Q27. Allylic halides are:
A. Less reactive than primary haloalkanes
B. More reactive due to resonance stabilization of carbocation
C. Non-reactive
D. Same as tertiary
Q28. Benzylic halides are:
A. Less reactive
B. Highly reactive in SN1 and SN2
C. Only undergo elimination
D. Only aromatic substitution
Q29. Reaction of CH₃CH₂Cl with KCN gives:
A. CH₃CH₂CN
B. CH₃CH₂OH
C. CH₃CH₃
D. CH₂=CH₂
Q30. Haloarenes are resistant to:
A. Electrophilic substitution
B. Nucleophilic substitution
C. Free radical halogenation
D. Friedel-Crafts reaction
Q31. CH₃CHClCH₃ reacts with alcoholic KOH to give:
A. CH₃CH=CH₂
B. CH₃CH₂CH₃
C. CH₂ClCH₂CH₃
D. CH₃CHOHCH₃
Q32. The major product of bromination of benzene is:
A. Bromobenzene
B. 1,2-dibromoethane
C. Benzyl bromide
D. Bromoform
Q33. CH₃CH₂Cl reacts with aqueous KOH via:
A. SN2 → CH₃CH₂OH
B. SN1 → CH₃CH₂OH
C. Free radical
D. Elimination
Q34. Chlorobenzene reacts with Br₂ in FeBr₃ to give:
A. C₆H₅Br
B. Benzyl bromide
C. Phenol
D. C₆H₅Cl
Q35. The order of reactivity in SN2 reactions:
A. Primary > Secondary > Tertiary
B. Tertiary > Secondary > Primary
C. Secondary > Primary > Tertiary
D. Equal
Q36. The order of reactivity in SN1 reactions:
A. Tertiary > Secondary > Primary
B. Primary > Secondary > Tertiary
C. Secondary > Primary > Tertiary
D. Equal
Q37. Which halogen is more reactive in free radical halogenation?
A. Cl
B. Br
C. I
D. F
Q38. CH₃CCl₃ reacts with KOH (alcoholic) to give:
A. CH₂=CCl₂
B. CH₃CH=CH₂
C. CH₃CH₂CH₃
D. CH₃CCl₂OH
Q39. Haloarenes undergo nucleophilic substitution more easily if:
A. Electron-withdrawing group is ortho/para to halogen
B. Electron-donating group is ortho/para to halogen
C. Halogen is on sp³ carbon
D. Halogen is tertiary
Q40. Grignard reagent reacts with CO₂ to give:
A. Carboxylic acid
B. Alcohol
C. Aldehyde
D. Ketone
Q41. Which of the following is tertiary halide?
A. (CH₃)₃CBr
B. CH₃CH₂CH₂Br
C. CH₃CHBrCH₃
D. CH₃CH₂Cl
Q42. Which halide undergoes Wurtz reaction fastest?
A. Primary
B. Secondary
C. Tertiary
D. Aryl
Q43. Chlorobenzene + NaOH (fused) →
A. Phenol
B. Benzyl alcohol
C. Benzene
D. Nitrobenzene
Q44. Allylic halide + KOH →
A. Alkene
B. Alcohol
C. Alkane
D. Phenol
Q45. Which reagent converts alcohol to haloalkane?
A. SOCl₂
B. NaOH
C. KCN
D. H₂
Q46. Sandmeyer reaction uses:
A. CuCl, CuBr, or CuCN
B. KOH
C. NaNH₂
D. HCl
Q47. Aryl halides do not undergo:
A. SN2 reaction
B. Electrophilic substitution
C. Nucleophilic substitution (under normal conditions)
D. Friedel-Crafts reaction
Q48. Which of the following is an example of benzylic halide?
A. C₆H₅CH₂Cl
B. C₆H₅Cl
C. CH₃CH₂Cl
D. CH₃CH₂CH₂Cl
Q49. Reactivity of haloalkanes in SN1:
A. Tertiary > Secondary > Primary
B. Primary > Secondary > Tertiary
C. Secondary > Tertiary > Primary
D. Equal
Q50. Reactivity of haloalkanes in SN2:
A. Primary > Secondary > Tertiary
B. Tertiary > Secondary > Primary
C. Secondary > Primary > Tertiary
D. Equal
Q1. B – Functional group is halogen (–X).
Q2. A – CH₃CH₂CH₂Cl is 1-Chloropropane.
Q3. B – (CH₃)₃CCl is tertiary (C bonded to three other C).
Q4. B – Haloarenes have halogen on sp² carbon → resonance stabilization reduces reactivity.
Q5. A – C₆H₅Cl is an aryl halide (halogen attached to benzene ring).
Q6. B – Alcohols react with PCl₅, SOCl₂, or PX₃ to form alkyl halides.
Q7. A – Tertiary haloalkanes react via SN1 (carbocation intermediate).
Q8. B – Primary haloalkanes react via SN2 (backside attack).
Q9. A – Chlorobenzene reacts with NaOH (fused) to give phenol.
Q10. A – Wurtz reaction works with primary haloalkanes.
Q11. A – SN2: Primary > Secondary > Tertiary (less steric hindrance).
Q12. A – SN1: Tertiary > Secondary > Primary (more stable carbocation).
Q13. A – KOH provides OH⁻ nucleophile.
Q14. C – Free radical halogenation occurs under UV light.
Q15. A – Alcoholic KOH eliminates HCl → CH₃CH=CH₂ (alkene).
Q16. A – Sandmeyer reaction converts aryl diazonium salts to aryl halides using CuX.
Q17. B – Halogen on benzene is less reactive due to resonance.
Q18. A – Nitrobenzene is formed by nitration (HNO₃ + H₂SO₄).
Q19. B – Haloarenes are less reactive than haloalkanes toward nucleophilic substitution.
Q20. A – Benzyl chloride + aqueous KOH → benzyl alcohol.
Q21. A – CH₃CH₂Br + Mg in dry ether → CH₃CH₂MgBr (Grignard reagent).
Q22. A – Tertiary halides undergo SN1 easily due to stable carbocation.
Q23. A – Free radical halogenation: tertiary > secondary > primary (stability of radical).
Q24. A – CH₂Cl group on benzyl position → CH₂OH (benzyl alcohol).
Q25. A – Chlorobenzene + NaNH₂ → Aniline (via nucleophilic aromatic substitution with –NH₂).
Q26. A – C–X bond in haloalkanes is polar covalent.
Q27. B – Allylic halides are more reactive due to resonance-stabilized carbocation.
Q28. B – Benzylic halides are highly reactive in SN1 and SN2.
Q29. A – CH₃CH₂Cl + KCN → CH₃CH₂CN (nucleophilic substitution).
Q30. B – Haloarenes resist nucleophilic substitution under normal conditions.
Q31. A – Alcoholic KOH causes elimination → alkene.
Q32. A – Bromination of benzene → bromobenzene via electrophilic substitution.
Q33. A – Primary haloalkane reacts via SN2 → CH₃CH₂OH.
Q34. A – Chlorobenzene + Br₂/FeBr₃ → C₆H₅Br (electrophilic aromatic substitution).
Q35. A – SN2: Primary > Secondary > Tertiary.
Q36. A – SN1: Tertiary > Secondary > Primary.
Q37. B – Br is more selective than Cl in free radical halogenation.
Q38. A – Alcoholic KOH eliminates HCl → CH₂=CCl₂.
Q39. A – Electron-withdrawing groups activate halogen for nucleophilic substitution.
Q40. A – Grignard + CO₂ → carboxylic acid after hydrolysis.
Q41. A – (CH₃)₃CBr is tertiary (C bonded to three other C).
Q42. A – Primary halides react fastest in Wurtz reaction due to less steric hindrance.
Q43. A – Chlorobenzene + NaOH (fused) → phenol.
Q44. A – Allylic halides + KOH → alkene (elimination).
Q45. A – Alcohol → haloalkane using SOCl₂, PCl₅, PX₃.
Q46. A – Sandmeyer uses CuCl, CuBr, CuCN to replace diazonium group.
Q47. A – Haloarenes do not undergo SN2 due to sp² hybridized carbon.
Q48. A – C₆H₅CH₂Cl is a benzylic halide.
Q49. A – SN1: tertiary > secondary > primary.
Q50. A – SN2: primary > secondary > tertiary.
Disclaimer:
All MCQs and solutions are educational, and for practice purposes only. They are based on NCERT and NEET syllabus and are not official NEET questions.