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

2. Predict the final organic product (P) of the following sequence:

3. The reaction of Toluene with an excess of Bromine () in the presence of yields the major organic product (Y). What is (Y)?

4. The resonance energy of benzene is approximately . This high resonance energy indicates that benzene is:

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

6. In an organic compound containing both a double bond and a triple bond, which functional group is prioritized in determining the parent chain and the suffix?

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

8. How many total structural isomers (including chain and position) are possible for the molecular formula ? (Exclude geometrical isomers).

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

10. Which of the following is the standard reagent and catalyst system required for the chlorination of benzene?

11. When 2-Bromobutane is treated with a strong base (like alcoholic ), which alkene is the major product according to Saytzeff's rule?

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

13. How are the substituents listed in the final IUPAC name if there are multiple different alkyl groups (e.g., methyl and ethyl)?

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

15. According to Molecular Orbital theory, the six electrons in benzene are delocalized over how many carbon atoms?

16. The lack of free rotation about a bond, as opposed to a bond, leads to which specific type of isomerism?

17. The intermediate compound formed immediately after the reaction of an alkene with ozone () but before the workup is called a:

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

19. Which of the following human activities is LEAST likely to produce or expose individuals to significant amounts of PAHs?

20. 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:

21. 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:

22. Which of the following alkanes can be prepared in good yield by the Wurtz reaction using only a single type of alkyl halide?

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

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

25. Which reaction is used to selectively form a cis-alkene from an alkyne?

26. According to Hückel's Rule, which of the following -electron counts is characteristic of an anti-aromatic compound?

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

28. How many bonds and bonds are present in the benzene molecule ()?

29. Which of the following constitutional (structural) isomers of has a four-carbon parent chain?

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

1. 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?

2. The alkene that yields only (Acetone) upon ozonolysis is:

3. If 1-Chloropropane is used in the Wurtz reaction, what is the structure of the major alkane product formed?

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

5. Hydrocarbons are primarily composed of which two elements?

6. How are the substituents listed in the final IUPAC name if there are multiple different alkyl groups (e.g., methyl and ethyl)?

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

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

9. 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:

10. The reaction of an alkene with cold, dilute, aqueous (Bayer's reagent) leads to the formation of which class of compounds?

11. The halogenation of benzene requires a catalyst, specifically a Lewis acid, because:

12. The lack of free rotation about the carbon-carbon double bond in alkenes is responsible for which type of isomerism?

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

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

15. What is the common name of the alkane with four carbon atoms that exhibits chain isomerism with -Butane?

16. In an organic compound containing both a double bond and a triple bond, which functional group is prioritized in determining the parent chain and the suffix?

17. What is the final step in the electrophilic substitution mechanism, which re-establishes the aromaticity of the ring?

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

19. What is the IUPAC name for the structure ?

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

21. Which of the following constitutional (structural) isomers of has a four-carbon parent chain?

22. In the reaction of Benzene with 1-Chloropropane and , the major product obtained is Isopropylbenzene (Cumene), not Propylbenzene. This is a direct consequence of:

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

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

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

26. Decarboxylation is considered a useful method for:

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

28. What is the IUPAC name of the product obtained when Ethyne reacts with excess Bromine water ( in )?

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

30. Which rule governs the major product formed during the dehydrohalogenation (removal of ) of a secondary alkyl halide?

31. What is the correct IUPAC name for the aromatic compound with two nitro groups attached to the benzene ring at positions 1 and 4?

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

33. Which reagent can be used to distinguish between a terminal alkyne (like Prop-1-yne) and an internal alkyne (like But-2-yne)?

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

35. The reaction of Ethyne with hydrogen gas () in the presence of Nickel () catalyst yields which final product?

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

37. Desulfonation (the reversal of sulfonation) is often used in synthesis for which of the following purposes?

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

39. According to Hückel's Rule, which of the following -electron counts is characteristic of an anti-aromatic compound?

40. 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:

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

42. When Propyne is treated with dilute in the presence of (Kucherov's reaction), the final stable product obtained is:

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

44. Which of the following intermediates is formed at the anode during the Kolbe's electrolytic synthesis of alkynes?

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

46. What is the hybridization of the carbon atoms in the Polyethylene polymer chain?

47. The reaction of Ethyne with cold, dilute (Bayer's reagent) yields which product?

48. Polyvinyl Chloride (PVC) is considered a thermoplastic material, meaning it:

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

50. The halogenation of alkanes (e.g., chlorination in the presence of sunlight) proceeds through which general reaction mechanism?