JEE Main - Homolytic and heterolytic bond fission radicals carbocations carbanions Online Test (MCQ Quiz)

1. What type of bond fission involves the symmetrical distribution of bonding electrons between the two atoms?

A) Heterolytic fission B) Homolytic fission C) Ionic fission D) Acidic fission

2. Which type of bond fission results in the formation of ions with opposite charges?

A) Homolytic fission B) Heterolytic fission C) Radical fission D) Free radical fission

3. What is the primary product of homolytic fission of a covalent bond?

A) Carbocation B) Carbanion C) Free radical D) Anion

4. Which species possesses a positive charge and an incomplete octet, formed by heterolytic fission?

A) Carbanion B) Free radical C) Carbocation D) Anion

5. What is a carbanion?

A) A species with a positive charge and an incomplete octet B) A species with a negative charge and a lone pair of electrons on a carbon atom C) A neutral species with an unpaired electron D) A positively charged carbon atom with an unpaired electron

6. Which of the following is characteristic of a free radical?

A) It has a full octet of electrons. B) It contains an unpaired electron. C) It carries a net positive charge. D) It carries a net negative charge.

7. What is the typical driving force for heterolytic fission?

A) High temperature B) Presence of a polar solvent C) UV light irradiation D) Presence of a catalyst

8. Homolytic fission is often initiated by:

A) Polar solvents B) Strong acids C) Heat or light energy D) Electrophilic reagents

9. Which of the following is an example of a carbocation?

A) CH3- B) CH3• C) CH3+ D) CH3Cl

10. Which of the following is an example of a carbanion?

A) CH3+ B) CH3• C) CH3Cl D) CH3-

11. Which of the following is an example of a free radical?

A) CH3+ B) CH3- C) CH3Cl D) CH3•

12. In the heterolytic fission of HCl, which species receives both electrons from the covalent bond?

A) H B) Cl C) Both H and Cl equally D) Neither H nor Cl

13. The stability of carbocations follows the order:

A) Tertiary > Secondary > Primary B) Primary > Secondary > Tertiary C) Methyl > Primary > Secondary D) Tertiary > Primary > Secondary

14. The stability of carbanions generally follows the order:

A) Primary > Secondary > Tertiary B) Tertiary > Secondary > Primary C) Methyl > Primary > Secondary D) Secondary > Primary > Tertiary

15. Which factor contributes to the stability of carbocations?

A) Electron-withdrawing inductive effect B) Electron-donating inductive effect C) Lone pair repulsion D) High electronegativity of the carbon atom

16. Which factor contributes to the stability of carbanions?

A) Electron-donating inductive effect B) Electron-withdrawing inductive effect C) Positive hyperconjugation D) Electron deficiency

17. Which of the following is the most stable carbocation?

A) Ethyl carbocation B) Isopropyl carbocation C) n-Propyl carbocation D) Methyl carbocation

18. Which of the following is the least stable carbanion?

A) Methyl carbanion B) Ethyl carbanion C) t-Butyl carbanion D) Isopropyl carbanion

19. What is the hybridization of the carbon atom in a methyl carbocation (CH3+)?

A) sp3 B) sp2 C) sp D) s

20. What is the hybridization of the carbon atom in a methyl carbanion (CH3-)?

A) sp B) sp2 C) sp3 D) d

21. What is the hybridization of the carbon atom in a methyl radical (CH3•)?

A) sp2 B) sp3 C) sp D) p

22. Which type of intermediate is involved in electrophilic addition reactions?

A) Carbanion B) Free radical C) Carbocation D) Carbene

23. Which type of intermediate is involved in nucleophilic substitution reactions of alkyl halides?

A) Carbocation B) Carbanion C) Free radical D) Carbene

24. Reactions involving free radicals are often characterized by:

A) Polar mechanisms B) Chain mechanisms C) Ionic mechanisms D) Concerted mechanisms

25. Which of the following is a source of free radicals?

A) Reaction in polar solvents B) Peroxides and UV light C) Strong nucleophiles D) Electrophilic catalysts

26. A carbocation is a Lewis:

A) Base B) Acid C) Radical D) Nucleophile

27. A carbanion is a Lewis:

A) Acid B) Base C) Radical D) Electrophile

28. Which of the following species is most likely to undergo rearrangement to form a more stable carbocation?

A) Methyl carbocation B) Ethyl carbocation C) Isopropyl carbocation D) n-Propyl carbocation

29. The term 'fission' in chemistry refers to:

A) Bond formation B) Bond breaking C) Electron sharing D) Proton transfer

30. Which of the following is an electrophile?

A) Carbanion B) Carbocation C) Ammonia D) Water

31. Which of the following is a nucleophile?

A) Carbocation B) Boron trifluoride C) Carbanion D) Hydrogen ion

32. What is the geometry around the carbon atom in a carbocation?

A) Tetrahedral B) Trigonal planar C) Linear D) Pyramidal

33. What is the geometry around the carbon atom in a carbanion?

A) Trigonal planar B) Tetrahedral C) Linear D) Square planar

34. The stability of free radicals generally follows the order:

A) Tertiary > Secondary > Primary B) Primary > Secondary > Tertiary C) Methyl > Primary > Secondary D) Secondary > Primary > Tertiary

35. Which type of bond fission is more common in non-polar solvents?

A) Heterolytic fission B) Homolytic fission C) Ionic fission D) Polar fission

36. Which type of bond fission is more common in polar solvents?

A) Homolytic fission B) Heterolytic fission C) Radical fission D) Thermal fission

37. Allylic and benzylic carbocations are more stable than simple alkyl carbocations due to:

A) Inductive effect only B) Hyperconjugation only C) Resonance stabilization D) Steric hindrance

38. Allylic and benzylic carbanions are more stable than simple alkyl carbanions due to:

A) Inductive effect B) Resonance stabilization C) Steric effects D) Lone pair repulsion

39. The formation of free radicals from halogens like Cl2 and Br2 is typically initiated by:

A) Polar solvents B) Strong bases C) Heat or UV light D) Nucleophilic attack

40. Which species has an electron deficiency at the carbon atom?

A) Carbanion B) Carbocation C) Free radical D) Alkyl halide

41. Which species has an excess of electrons at the carbon atom?

A) Carbocation B) Free radical C) Carbanion D) Borane

42. What is the term for a species that contains an unpaired electron and is highly reactive?

A) Carbocation B) Carbanion C) Free radical D) Carbene

43. Consider the heterolytic fission of CH3Br. The bromide ion (Br-) is formed because:

A) Bromine is more electronegative than carbon B) Bromine is less electronegative than carbon C) Carbon has an unpaired electron D) The C-Br bond is ionic

44. Which of the following is a possible intermediate in the free radical halogenation of alkanes?

A) CH3+ B) CH3- C) CH3• D) CH3Cl

45. The stability of carbocations is enhanced by:

A) Electron-withdrawing groups B) Electron-donating groups C) Steric hindrance D) Lone pair repulsion

46. The stability of carbanions is enhanced by:

A) Electron-donating groups B) Electron-withdrawing groups C) Steric repulsion D) Positive charge

47. What kind of species is BF3, which can accept a pair of electrons?

A) Lewis Base B) Lewis Acid C) Brønsted-Lowry Acid D) Brønsted-Lowry Base

48. What kind of species is NH3, which can donate a pair of electrons?

A) Lewis Acid B) Lewis Base C) Brønsted-Lowry Acid D) Oxidizing Agent

49. In the context of organic reaction mechanisms, what does a curved arrow typically represent?

A) Movement of atoms B) Movement of electrons C) Movement of protons D) Bond formation

50. A single-headed curved arrow in reaction mechanisms signifies the movement of:

A) A pair of electrons B) A single electron C) An atom D) A proton

Homolytic and heterolytic bond fission radicals carbocations carbanions - Online Test

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