Haloalkanes and Haloarenes Mock Test – Class 12 Chemistry

1. Match each treatment of chlorobenzene with its principal product class.

Which evaluation is appropriate?

2. An ideal reaction has an initial rate of when . The rate constant is:

3. For the first-order rate law , the standard unit of the rate constant is ______.

4. A learner claims that the Fittig reaction is the standard sodium-coupling method for converting chlorobenzene and chloromethane into toluene. The claim is:

5. Under conditions in which carbon–halogen bond ionisation is significant, allyl chloride generally reacts more readily than -chloropropane because:

6. A reaction-coordinate graph for benzene chlorination shows two pathways with the same reactant and product energy levels. The curve for the -catalysed pathway has a lower maximum than the uncatalysed curve. The graph indicates that :

7. The ideal rate law for an reaction between a haloalkane and a nucleophile is:

8. The primary, secondary, or tertiary classification of a monohaloalkane is determined by:

9. Identify the rows that represent propagation steps in methane chlorination.

10. A reliable comparison of the and bond lengths should preferably be made between:

11. Interpret the following statements about ordinary nucleophilic substitution in chlorobenzene.
Statement I: Resonance gives the carbon–chlorine bond partial double-bond character.
Statement II: The chlorine-bearing carbon is -hybridised.
Statement III: A simple pathway would require an unstable phenyl carbocation.
Statement IV: A normal alkyl-halide-type backside approach is difficult.

Which option is correct?

12. Evaluate the following conversions of bromoethane.

The appropriate evaluation is:

13. Four cyanide-substitution records are shown.
P. gives .
Q. gives .
R. gives .
S. gives .

Choose the appropriate evaluation.

14. Dichloromethane can function as an extraction solvent in a liquid–liquid process mainly because it:

15. The claim “Choosing a polar aprotic solvent is sufficient to make every haloalkane react by ” is:

16. Match each item in Column I with the appropriate description in Column II.

17. Four bromides are tested under two sets of conditions.

P.
Q.
R.
S.

Condition 1 uses in a polar aprotic solvent. Condition 2 uses aqueous ethanol.

Which interpretation is most reasonable?

18. Chlorocyclohexane is classified as a secondary haloalkane because the ring carbon bonded to chlorine:

19. Under identical conditions, the rate constants for benzyl bromide and bromoethane are and , respectively. At equal substrate and nucleophile concentrations, the benzyl bromide reaction is faster by a factor of:

20. tert-Butylbenzene, , does not undergo the usual direct benzylic hydrogen substitution at the carbon attached to the ring because:

21. A practical notebook contains the following proposed diazonium conversions.

The row that requires correction is:

22. Match each structure in Column I with its classification in Column II.

23. The principal organic product formed when -bromobutane is heated with in dry acetone is:

24. The structure that represents a benzylic halide is:

25. Assertion: Carbon tetrachloride has zero molecular dipole moment.
Reason: Its four identical carbon–chlorine bond dipoles are arranged symmetrically and cancel vectorially.

26. Aniline is converted into benzenediazonium chloride by treating it with:

27. A four-carbon chain is written as . Its IUPAC name is:

28. Match each reaction in Column I with its classification in Column II.

29. Four halo compounds are tested under conditions chosen for their characteristic reactions.
P. with a strong nucleophile in a polar aprotic solvent
Q. in aqueous ethanol
R. with aqueous hydroxide
S. with mild aqueous hydroxide
Select the combined interpretation supported by these tests.

30. A learner numbers from the left and obtains -chlorobutane. The required correction is:

31. The claim “Every carbocation formed in an reaction must rearrange” is:

32. The compound is best described as:

33. The proposed first step

is highly unfavourable in an ordinary reaction mainly because:

34. A Finkelstein-reaction record contains three proposed outcomes.
P. in dry acetone gives .
Q. in dry acetone gives .
R. in dry acetone rapidly gives .

Select the appropriate evaluation.

35. Analyse the following ideal stereochemical outcomes.

The appropriate evaluation is:

36. An aromatic-ring carbon in benzene belongs to an aryl skeleton and has which hybridisation?

37. Assertion: Vinyl chloride does not readily undergo ordinary substitution.
Reason: Formation of a vinyl carbocation would place the positive charge on a double-bonded carbon and produce a highly unstable intermediate.

38. The compound is commonly called:

39. The formula of the chlorofluorocarbon commonly represented as Freon-12 is:

40. Tertiary carbocations are generally more stable than secondary and primary alkyl carbocations mainly because:

41. The general equation that best represents nucleophilic substitution of a haloalkane is:

42. Benzyl bromide reacts mainly by in aqueous ethanol but mainly by with in a polar aprotic solvent. The best explanation is:

43. Assertion: tert-Butyl chloride is a primary haloalkane because each of its three methyl groups contains a primary carbon.
Reason: The carbon directly bonded to chlorine in tert-butyl chloride is attached to three other carbon atoms.

44. The pair and illustrates:

45. A sample of carbon tetrachloride has molar mass . How many moles of chlorine atoms are present?

46. A substitution rate is unchanged when nucleophile concentration is tripled, but it doubles when haloalkane concentration is doubled. This kinetic behaviour supports:

47. Review the following Wurtz-reaction product assignments.

The appropriate evaluation is:

48. Neopentyl chloride, , is classified as a primary haloalkane because:

49. The balanced equation for converting an alcohol into an alkyl chloride using thionyl chloride is:

50. Use the arrangement . A halogen attached to gives a vinylic halide, whereas attachment to gives: