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

2. The initial, slower step in the reaction between benzene and is rate-determining. This involves the breaking of the aromaticity and has a high activation energy, characteristic of:

3. What is the correct name for the compound ?

4. The number of chain isomers possible for the molecular formula (Pentane) is:

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

6. What is the necessary condition or reagent (Z) to carry out the following transformation from Chlorobenzene to Benzene?

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

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

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

10. Which halogen reacts the fastest with methane in a free-radical substitution reaction?

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

12. The sulfonation of benzene is best carried out using which reagent system to maximize the yield of benzenesulfonic acid?

13. When a substituent donates electrons to the ring via resonance, the electron density is primarily increased at which positions?

14. Which of the following substituents is categorized as a deactivating and -directing group?

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

16. What is the general molecular formula for acyclic alkynes containing one carbon-carbon triple bond?

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

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

19. A significant limitation shared by both Friedel–Crafts alkylation and acylation is that the reaction:

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

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

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

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

24. 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?

25. What is the correct IUPAC name for the alkane structure ?

26. Anthracene () is a three-ring PAH. Compared to its isomer, Phenanthrene, Anthracene is generally considered to be:

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

28. Which of the following is a disadvantage of the Kolbe's electrolytic synthesis method for preparing alkanes?

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

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

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

2. Decarboxylation is considered a useful method for:

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

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

5. What is the correct name for the compound ?

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

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

8. Dehydrohalogenation of an unsymmetrical vicinal dihalide (e.g., 1,2-Dibromobutane) will preferentially form the internal alkyne (But-2-yne) over the terminal alkyne (But-1-yne). This is because the internal alkyne is:

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

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

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

12. Which type of isomerism is characterized by having the same molecular formula and the same carbon skeleton, but differing in the position of the functional group or substituent?

13. What is the correct IUPAC name for the alkane structure ?

14. According to Hückel's rule, for a compound to be considered aromatic, the number of electrons in the fully conjugated cyclic system must satisfy which formula?

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

16. When is added to an alkene in the presence of an organic peroxide (like benzoyl peroxide), the reaction is said to follow:

17. 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:

18. The number of chain isomers possible for the molecular formula (Pentane) is:

19. If a benzene ring is substituted with both a group (strongly activating, ) and a atom (deactivating, ), where will the next electrophile predominantly substitute?

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

21. What is the function of the zinc dust () and water workup () step after the initial reaction of the alkene with ozone ()?

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

23. The reaction of an internal alkyne with in an inert solvent results in the formation of a product with which stereochemistry?

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

25. What is the molecular formula for -Hexane?

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

27. Which halogen reacts the fastest with methane in a free-radical substitution reaction?

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

29. A hydrocarbon has the molecular formula . How many possible positional isomers are there if the parent chain is kept as a straight chain (Hexane)?

30. Which set of reagents is used to convert an alkene to a corresponding alkane?

31. In the decarboxylation reaction using soda lime, the role of Calcium Oxide () is primarily to:

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

33. The electrolysis of an aqueous solution of sodium ethanoate () using the Kolbe's method produces which main product at the anode?

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

35. 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:

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

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

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

39. 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?

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

41. What is the minimum number of carbon atoms required for a compound to be classified as an alkyne?

42. Kolbe's electrolytic method for the preparation of alkynes involves the electrolysis of the potassium or sodium salt of which specific class of organic compounds?

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

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

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

46. Terminal alkynes (e.g., Ethyne) are characterized by the presence of an acidic hydrogen atom. The acidity is primarily due to the:

47. But-1-yne and Buta-1,3-diene are examples of which type of isomerism?

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

49. The single bond length in propane is . This bond is formed by the overlap of which types of orbitals from the two adjacent carbon atoms?

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