Hydrocarbons Mock Test – Class 11 Chemistry

1. Open-chain hydrocarbons such as straight-chain alkanes, alkenes, and alkynes are usually grouped under

2. Markovnikov addition of to an unsymmetrical alkene is best interpreted as

3. Complete combustion of of an open-chain alkane requires of . The alkane is

4. A benzene ring already contains at position . If it undergoes chlorination under electrophilic substitution conditions, the major product is expected to have chlorine mainly at

5. A desired alkane is propane, . Wurtz preparation from a single alkyl halide is not the best direct choice because

6. The solvent most suitable for dissolving an alkane is generally

7. Methane, , is used as a simple model for alkane bonding because its carbon atom

8. Addition of to propene in the absence of peroxide mainly gives

9. If benzene is converted first to nitrobenzene and then nitrated again, the main disubstituted product is

10. In naming an alkene, the parent chain must be chosen so that it

11. For straight-chain alkanes, the boiling point generally increases from methane to higher members because

12. A claim says, “The formula proves a compound is but--yne.” The better conclusion is that

13. A table compares roles in electrophilic addition of to an alkene.

The entry that needs correction is

14. Reductive ozonolysis gives two molecules of ethanal from hydrocarbon , and also has geometrical isomers. The most suitable identity of is

15. A vicinal dibromide has the structure . Treatment with zinc dust gives

16. A reagent list for converting an alkyl halide into an alkane includes

17. The relatively higher acidity of terminal alkynes compared with alkenes is mainly due to the

18. A table lists possible additions of hydrogen halides to alkenes.

The row that needs correction is

19. A compound decolourises both bromine water and dilute alkaline at room temperature. The most likely structural feature in is

20. Ammoniacal silver nitrate can distinguish a terminal alkyne because a terminal alkyne forms

21. Open-chain alkyne produces of on complete combustion of . Complete addition of bromine to the same amount of requires

22. A reaction condition uses aqueous instead of alcoholic with an alkyl halide. The expected reaction tendency changes because aqueous more commonly favours

23. Combustion results for hydrocarbon give of and of from of . It also consumes of per during complete hydrogenation. The formula of is

24. A learner claims, “Every hydrocarbon with fewer hydrogen atoms than the corresponding alkane must behave like a simple alkene.” The best response is that

25. Consider the following statements about hydrocarbon bonding.
I. Hydrocarbons contain covalent bonds.
II. Carbon atoms in hydrocarbons may join to other carbon atoms.
III. A hydrocarbon must contain oxygen if it is organic.

26. A conformation record gives the following energy values for ethane:

The rotational energy barrier from staggered to eclipsed is

27. A record of alkane structures is shown below.

The row that needs correction is

28. Nitration and flame observations identify compound , formula , which burns with a smoky flame and gives one mononitro product with . The most suitable identity is

29. Among the following substances, the hydrocarbon is the one represented by

30. In the name , the structural information is interpreted as

31. Assertion: A methyl group directs incoming electrophiles mainly to ortho and para positions in benzene substitution.
Reason: The methyl group increases electron density at ortho and para positions through electron-releasing effects.

32. A mixture of benzene and styrene, , contains total hydrocarbon. It consumes of in a rapid addition test and gives of on complete combustion. The moles of benzene in the mixture are

33. Nitration of alkanes, when treated at the introductory level, is generally associated with

34. A learner expects three different monobromobenzenes because benzene can be drawn with alternating double bonds. The best correction is that

35. Ordinary and peroxide-controlled additions give different bromopropanes: without peroxide and with peroxide. The starting hydrocarbon is

36. The balanced complete combustion equation for methane is

37. A naming note gives two possible numberings for the same substituted alkane: substituent locants or . The preferred set is

38. A reaction map is shown below.

The row that needs correction is

39. A table compares alkyl halide conversion routes.

The row that needs correction is

40. A Newman projection of ethane is drawn by looking

41. The decolourisation of dilute alkaline by an alkene is used as a test for

42. A molecule written as contains only carbon and hydrogen. At this stage, the safest classification from composition alone is that it is

43. The expression “carbon skeleton” in a hydrocarbon mainly refers to

44. An alkyne sample of reacts completely with excess bromine to form a tetrabromoalkane and consumes of . On combustion, the same amount of gives of . The molecular formula of is

45. The pair and is best described as

46. Ethyne reacts with sodium metal to form sodium acetylide and hydrogen gas. The reaction is best represented as

47. A compound is heated with alcoholic . The alkene formed is

48. A hydrocarbon has one tertiary hydrogen and nine primary hydrogens. On radical bromination, the major monobromo product is expected from replacement of

49. In comparing ethene, propene, and butene under ordinary physical-property trends, the strongest reason for increasing boiling point is the increase in

50. A graph compares relative reaction rate for electrophilic substitution of three aromatic compounds: toluene, benzene, and nitrobenzene. The highest bar should correspond to