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

3. A compound is classified as non-aromatic if:

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

5. What is the molecular formula for -Hexane?

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

7. The nitrating mixture is formed by the equilibrium reaction: . Which substance acts as the base in this equilibrium?

8. The second elimination step, converting a haloalkene into an alkyne, is often difficult because it removes a hydrogen from a carbon that is part of a double bond. What extremely strong base is required to complete this step, especially for terminal alkynes?

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

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

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

12. Chain isomerism is not possible for which of the following simple alkanes?

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

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

15. Ozonolysis of Propene () followed by reductive workup yields which two main products?

16. The intermediate formed by the reaction of the electrophile () and the benzene ring is known as the complex. This intermediate is stabilized by:

17. The nitration of benzene is an example of which general class of organic reaction?

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

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

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

21. A compound with the molecular formula can represent either a simple alkyne or:

22. Which of the following substituents is a strongly activating and -directing group?

23. The reaction of an alkene with hydrogen gas () in the presence of a metal catalyst (, , or ) is known as:

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

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

26. Which product is formed when Propene () reacts with water in the presence of an acid catalyst ()?

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

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

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

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

1. The addition of to Ethene is a test for unsaturation. The mechanism for this reaction is an example of:

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

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

4. Chain isomerism is not possible for which of the following simple alkanes?

5. Which of the following is an advantage of Friedel–Crafts Acylation over Alkylation?

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

7. The decolorization of an aqueous solution of cold, dilute, alkaline potassium permanganate ( reagent) is a characteristic test for the presence of:

8. 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?

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

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

11. The initial step in the sulfonation of benzene involves the attack of the electrophile on the -cloud of benzene, forming an intermediate known as a:

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

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

14. Polynuclear Aromatic Hydrocarbons (PAHs) are primarily formed during:

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

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

18. The product of a Friedel–Crafts Acylation is generally less reactive toward a second electrophilic substitution than the starting benzene ring. This is due to the acyl group () being a:

19. The product formed when sodium propanoate () is heated with soda lime ( and ) is:

20. 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?

21. What is the general molecular formula for saturated open-chain hydrocarbons (Alkanes)?

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

23. What is the molecular formula for Cyclopentene?

24. What is the number of sigma bonds in the molecule -Butane ()?

25. Which of the following reagents will react with But-1-yne but not with But-2-yne?

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

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

28. All -directing groups are characterized by having:

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

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

31. Ethene () is the simplest alkene. Which of the following is true about its structure?

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

33. 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:

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

35. What is the value used in Hückel's rule ( electrons) for the benzene molecule?

36. The reduction of an alkyne with metal dissolved in liquid () primarily yields which isomeric product?

37. Which of the following compounds would require a high temperature and high pressure for substitution with an aqueous base ()?

38. The nitration of benzene is an example of which general class of organic reaction?

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

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

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

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

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

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

45. The reaction of an alkene with hydrogen gas () in the presence of a metal catalyst (, , or ) is known as:

46. What is the major product (M) of the reaction when Benzene is treated with in the presence of anhydrous , followed by and ?

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

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

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

50. Due to the bond, rotation about the carbon-carbon double bond in alkenes is: