Class 11 Chemistry — Chapter 13: Hydrocarbons Online Test

1. The term "polynuclear" in refers to the presence of:

2. The primary reason the Methyl group () is an activating and -directing group is its ability to donate electrons via:

3. When the product of a Friedel–Crafts acylation () is treated with and concentrated (Clemmensen Reduction), the final product obtained is a:

4. The final step in the halogenation mechanism is the regeneration of the catalyst and the aromatic ring. This involves the removal of which species from the complex?

5. In the reaction , the bond of the benzene ring is broken, and a new bond is formed. This step is a characteristic of:

6. The overall nitration reaction is written as: . How is this reaction classified in terms of heat change?

7. The initial slow step in the mechanism of benzene nitration involves the attack of the electrophile on the benzene ring to form:

8. The addition of water () to Ethyne () in the presence of and yields an intermediate enol, which quickly tautomerizes to form the final product:

9. After an alkyne salt () is formed using , how is the neutral terminal alkyne () typically regenerated?

10. Starting with 1,1-Dichloropropane and performing double dehydrohalogenation, what is the final alkyne product?

11. The carbon atoms involved in the triple bond of an alkyne are linked by which combination of bonds?

12. Ozonolysis of an unknown alkene yields () and (). Identify the structure of the starting alkene.

13. Halogenation of an alkene with or results in the formation of which type of product?

14. The conversion of a vicinal dihalide () to an alkene requires treatment with:

15. The compound 2,3-Dimethylbut-2-ene does not show geometrical isomerism because:

16. The two carbon atoms involved in the double bond of an alkene are linked by which combination of bonds?

17. Decarboxylation is considered a useful method for:

18. What is the molecular formula for -Hexane?

19. What is the approximate bond length in a typical alkyne, such as Ethyne ()?

20. How many sigma () and pi () bonds are present in Propene ()?

1. Which reagent combination is typically used for the decarboxylation of a sodium carboxylate salt () to form an alkane?

2. Which catalyst system is typically used in the industrial production of to create a highly linear polymer chain with minimal branching?

3. Which of the following is not a structural isomer of -Pentane ()?

4. How many possible structural (chain and positional) isomers are there for the alkane with the molecular formula (Hexane)?

5. The electrophile that attacks the benzene ring during the sulfonation reaction is the:

6. Identify the total number of primary carbon atoms in the structure of 2,2-Dimethylpropane (Neopentane).

7. The term "polynuclear" in refers to the presence of:

8. Which of the following PAHs is considered one of the most potent carcinogens and is found in high concentrations in cigarette smoke and coal tar?

9. Which catalyst is used to selectively stop the hydrogenation of an alkyne at the alkene stage (i.e., synthesize an alkene from an alkyne)?

10. Why does the Friedel–Crafts Alkylation reaction often result in polysubstitution (addition of multiple alkyl groups)?

11. Polymerization is generally defined as a chemical process where:

12. A major limitation of the Friedel–Crafts Alkylation reaction is the possibility of the alkyl group rearranging before attacking the benzene ring. This rearrangement occurs because the electrophile generated is often:

13. The treatment of Ethyne () with a hot iron tube at results in which major product?

14. What is the IUPAC name for the structure ?

15. Alkynes are classified as terminal or internal based on:

16. When an unsymmetrical alcohol like Pentan-2-ol is dehydrated, which type of alkene is predominantly formed?

17. The carbon atoms in an alkane chain are joined by which type of bond?

18. If an excess amount of Chlorine gas () is reacted with Methane () under high temperature or light, the final product of complete substitution is:

19. Which of the following classes of hydrocarbons is generally called Paraffins?

20. Hydrocarbons containing carbon-carbon double bonds are classified as:

21. What is the main limitation of the Wurtz reaction when attempting to prepare an unsymmetrical alkane, such as Propane?

22. Which of the following is an essential condition for two organic compounds to be structural isomers?

23. When But-2-ene () undergoes ozonolysis, the single organic product obtained after reductive workup is:

24. What is the main limitation of the Wurtz reaction for the preparation of alkanes?

25. Ozonolysis of Cyclohexene followed by reductive workup yields a single product, which is a:

26. What is the correct IUPAC name for the compound ?

27. The Kekulé structure of benzene proposed that the molecule has:

28. Which product is formed when Ethyne (Acetylene) is passed through a red-hot iron tube at ?

29. What is the molecular formula for Hex-1-yne?

30. When naming a substituted benzene derivative, the two substituents are at the 1 and 3 positions. Which common prefix is used to denote this arrangement?

1. Which pair of compounds represents functional group isomerism?

2. The alkyl halide used in the Wurtz reaction must be dissolved in which solvent for the reaction to proceed successfully?

3. If an excess amount of Chlorine gas () is reacted with Methane () under high temperature or light, the final product of complete substitution is:

4. What is the essential purpose of using concentrated sulfuric acid () along with concentrated nitric acid () in the nitration of benzene?

5. According to Markownikov's rule, the major product formed when is added to 2-Methylpropene () is:

6. What are the products of the complete combustion of any alkane in the presence of excess oxygen?

7. What is the sum of the stoichiometric coefficients of and in the balanced chemical equation for the complete combustion of Pentane ()?

8. A cyclic, planar, fully conjugated system that contains electrons (e.g., electrons) is classified as:

9. What is the minimum number of carbon atoms required for an alkene to exhibit positional isomerism?

10. What is the geometry and bond angle around the carbon atoms of the triple bond in a simple alkyne?

11. Why is benzene significantly more stable than a hypothetical cyclohexatriene structure with isolated double bonds?

12. How many sigma () and pi () bonds are present in Propene ()?

13. When the product of a Friedel–Crafts acylation () is treated with and concentrated (Clemmensen Reduction), the final product obtained is a:

14. The benzenesulfonic acid product can be readily converted into phenol () by first treating it with at high temperatures, followed by acidification. This conversion highlights the utility of the group as:

15. Which conformer of Ethane () represents the state of maximum stability and minimum energy?

16. The conversion of a compound from the enol form to the keto form is an example of which specialized type of isomerism?

17. What is the approximate length of the carbon-carbon bonds in the stable benzene ring?

18. When 1-Butene reacts with in the absence of peroxides, the major product is 2-Bromobutane. This is an example of an addition reaction that follows:

19. The formation of Polyethylene from Ethene is an example of which type of polymerization reaction?

20. What is the approximate range of the degree of polymerization (number of monomer units, ) in commercial polyethylene?

21. Which type of addition is characteristic of the reaction of with an alkene in an inert solvent?

22. When But-2-ene () undergoes ozonolysis, the single organic product obtained after reductive workup is:

23. When naming a substituted benzene derivative, the two substituents are at the 1 and 3 positions. Which common prefix is used to denote this arrangement?

24. The dehydrohalogenation of a terminal geminal dihalide (1,1-dihalide) primarily yields which type of alkyne?"

25. Polymerization is generally defined as a chemical process where:

26. Which product is formed when is added to a terminal alkyne like Prop-1-yne in the presence of and ?

27. What is the hybridization state of the two carbon atoms involved in the double bond of an alkene?

28. As a result of chain isomerism, how do the boiling points of the isomers generally change from the straight chain to the highly branched chain?

29. Which statement accurately describes the relationship between -Hexane and 2-Methylpentane?

30. Which reagent is typically used for the halogenation (e.g., chlorination) of Benzene to prevent addition and favor substitution?

31. Which catalyst is used to selectively stop the hydrogenation of an alkyne at the alkene stage (i.e., synthesize an alkene from an alkyne)?

32. The -electron count for the Pyridine molecule () is:

33. The correct representation of the -electron system in Benzene according to the Modern Theory is:

34. Which pair of compounds represents an example of chain isomerism?

35. Ozonolysis of 2-Butene () followed by treatment with yields which product?

36. The conversion of a higher alkane into an isomeric branched-chain alkane in the presence of an anhydrous aluminum chloride and hydrogen chloride is called:

37. An alkene yields one mole of and one mole of (Methyl Ethyl Ketone) upon ozonolysis. What was the starting alkene?

38. The two carbon atoms involved in the double bond of an alkene are linked by which combination of bonds?

39. When an unsymmetrical alcohol like Pentan-2-ol is dehydrated, which type of alkene is predominantly formed?

40. How many possible structural isomers exist for Dimethylbenzene (Xylene)?

41. The process of heating higher alkanes in the absence of air and often in the presence of a catalyst to break them into smaller, lower molecular mass hydrocarbons (alkanes and alkenes) is called:

42. Polyethylene (PE) is formed from the monomer Ethene. What is the repeating structural unit in the Polyethylene chain?

43. The bond angle around the carbon atoms of the double bond in an alkene is approximately:

44. The electrophilic substitution reactions are characteristic of aromatic compounds because:

45. The carbon-carbon triple bond length in Ethyne () compared to the double bond length in Ethene () and the single bond length in Ethane () is:

46. The terminal hydrogen atom of ethyne () is acidic because the carbon atom involved is:

47. The primary difference between a homopolymer (like polyethylene) and a copolymer is:

48. Which of the following numbers of electrons is consistent with Hückel's rule for an aromatic compound?

49. The first molecule of is added to an alkyne following which rule?

50. The electrophile that attacks the benzene ring during the nitration reaction is: