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

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

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

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

5. In the preparation of ethene () via Kolbe's electrolytic method, the starting material is the aqueous solution of the sodium or potassium salt of which carboxylic acid?

6. Which intermediate species is generated at the anode during the Kolbe's electrolytic synthesis of alkanes?

7. When Methane is heated with oxygen at high pressure () in the presence of Copper () catalyst, the primary product is:

8. Why are halogens (, ) unique among all substituents?

9. The preference of alkanes to undergo substitution reactions rather than addition reactions is due to:

10. Friedel–Crafts Acylation requires more than one full equivalent of the catalyst (often to equivalents). This is because:

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

12. How many total bonds and bonds are present in a molecule of But-2-yne ()?

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

14. Which of the following conditions is most suitable for the dehydrohalogenation of an alkyl halide ()?

15. A compound with the molecular formula can be either an alkene or a cycloalkane. This is an example of which type of isomerism?

16. The addition of to Propene () follows which of the following rules for predicting the major product?

17. Which type of hydrogen atom in an alkane is most easily substituted by a halogen atom () in a free-radical halogenation reaction?

18. The Cyclopropenyl cation (a three-membered ring with one positive charge) is aromatic because it satisfies Hückel's rule with which total number of electrons?

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

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

21. If the nitration of Toluene () is performed, the major products formed will be:

22. All -directing groups are characterized by having:

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

24. The difference between any two consecutive members in the Alkane homologous series is a unit of:

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

26. The -electron count in the smallest aromatic PAH, Naphthalene, is:

27. The cyclopentadienyl anion (a five-membered ring with one negative charge) is aromatic because it is cyclic, planar, fully conjugated, and contains:

28. The primary purpose of ozonolysis ( followed by ) in alkene chemistry is to:

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

30. If 1-Propanol () is dehydrated with concentrated at , what is the product?

1. What is the general molecular formula for acyclic alkenes containing one carbon-carbon double bond?

2. The reaction of an alkyne with (Hydrobromination) follows Markownikov's rule. Which product is formed when one equivalent of is added to Propyne ()?

3. The halogenation of alkanes (e.g., Chlorination of Methane) is an example of which type of organic reaction mechanism?

4. What is the principal functional group or structural feature that determines the suffix '-ene' in the IUPAC naming of an organic compound?

5. What is the molecular formula for the straight-chain alkane known as Heptane?

6. Which factor is most important in determining whether the dehydration of an alcohol will follow the or mechanism?

7. The compound Cyclooctatetraene () has electrons. Why is it considered non-aromatic rather than anti-aromatic?

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

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

10. As the degree of branching increases in isomeric alkanes, how does the boiling point generally change?

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

12. The hybridization of all six carbon atoms in the benzene ring is:

13. The hydrogenation of -Xylene () using and under mild conditions results in what major product (L)?

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

15. The primary purpose of ozonolysis ( followed by ) in alkene chemistry is to:

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

17. If Toluene is sulfonated at a low temperature (e.g., ), the major product is primarily the isomer. If the temperature is raised to , the major product shifts to the isomer. This phenomenon is an example of:

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

19. The decomposition of a higher alkane into a mixture of lower alkanes, alkenes, and hydrogen by heating it to a high temperature is called:

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

21. 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:

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

23. The resonance energy of Benzene, which quantifies its extra stability due to delocalization, is approximately:

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

25. What is the product formed after the first stage of chlorination of Methane () in the presence of UV light?

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

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

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

29. The hybridization of the carbon atoms involved in the triple bond of an alkyne is:

30. The Cyclopropenyl cation (a three-membered ring with one positive charge) is aromatic because it satisfies Hückel's rule with which total number of electrons?

31. What is the fundamental characteristic that gives aromatic compounds their exceptional stability?

32. The two main types of Polyethylene, Low-Density Polyethylene (LDPE) and High-Density Polyethylene (HDPE), primarily differ in their:

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

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

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

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

37. Which intermediate species is generated at the anode during the Kolbe's electrolytic synthesis of alkanes?

38. Which pair of compounds represents functional group isomerism?

39. Which of the following is the monomer used to produce Polyvinyl Chloride (PVC)?

40. Which type of hybridization is observed for all carbon atoms in the simplest member of the Alkyne family, Ethyne ()?

41. The primary reason why many larger PAHs, such as Benzo[a]pyrene, are potent carcinogens is that they:

42. A crucial difference in the required starting materials for Alkylation versus Acylation is that Acylation uses an acyl halide () or an acid anhydride, while Alkylation uses:

43. What are the products of the ozonolysis of 2-Methylbut-2-ene ()?

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

45. What is the approximate bond length in a typical alkene, such as Ethene ()?

46. 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:

47. A simple method often used to remove PAHs from contaminated water or industrial effluents relies on their property of being:

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

49. The carbon atoms at the ends of a straight-chain alkane are termed as:

50. If the temperature is too high during the nitration of benzene, the formation of which product is favored?