Tetravalency of carbon hybridization and shapes of simple molecules - Question Bank

1. Which of the following molecules has a central carbon atom that is sp² hybridized and exhibits a trigonal planar geometry?
A) Ethyne (C₂H₂)
B) Ethene (C₂H₄)
C) Methane (CH₄)
D) Ammonia (NH₃)
2. Which of the following molecules has a central carbon atom that is sp³ hybridized and exhibits a tetrahedral geometry?
A) Ethyne (C₂H₂)
B) Ethene (C₂H₄)
C) Methane (CH₄)
D) Carbon dioxide (CO₂)
3. The concept of hybridization helps explain:
A) The atomic number of elements
B) The magnetic properties of elements
C) The observed bond angles and molecular shapes
D) The ionization energies of elements
4. In a carbon atom forming a triple bond, how many pi bonds are present?
A) Zero
B) One
C) Two
D) Three
5. In a carbon atom forming a double bond, how many pi bonds are present?
A) Zero
B) One
C) Two
D) Three
6. Which type of overlap leads to the formation of pi bonds?
A) Head-on overlap of atomic orbitals
B) Sideways overlap of p orbitals
C) Overlap of hybrid orbitals
D) Overlap of s orbitals only
7. Which type of overlap leads to the formation of sigma bonds?
A) Sideways overlap of p orbitals
B) Head-on overlap of atomic orbitals
C) Overlap of hybrid orbitals
D) Both B and C
8. What is the approximate percentage of s-character in sp hybridization?
A) 33.3%
B) 25%
C) 50%
D) 75%
9. What is the approximate percentage of s-character in sp² hybridization?
A) 33.3%
B) 25%
C) 50%
D) 75%
10. What is the approximate percentage of s-character in sp³ hybridization?
A) 33.3%
B) 25%
C) 50%
D) 75%
11. The shape of a carbon free radical (e.g., CH₃•) is typically:
A) Linear
B) Trigonal planar
C) Tetrahedral
D) Pyramidal
12. The hybridization of carbon in a free radical (e.g., CH₃•) is generally considered to be:
A) sp
B) sp²
C) sp³
D) unhybridized
13. The C≡C triple bond length in ethyne (C₂H₂) is approximately:
A) 120 pm
B) 134 pm
C) 154 pm
D) 120 pm
14. The C=C double bond length in ethene (C₂H₄) is approximately:
A) 120 pm
B) 134 pm
C) 154 pm
D) 180 pm
15. The C-C single bond length in ethane (C₂H₆) is approximately:
A) 120 pm
B) 134 pm
C) 154 pm
D) 180 pm
16. In diamond, carbon atoms are hybridized as:
A) sp
B) sp²
C) sp³
D) unhybridized
17. In graphite, carbon atoms are hybridized as:
A) sp
B) sp²
C) sp³
D) unhybridized
18. What is the role of hybridization in explaining the shapes of molecules?
A) It determines the number of lone pairs
B) It describes the mixing of atomic orbitals to form new hybrid orbitals with specific spatial orientations
C) It dictates the polarity of the molecule
D) It explains the reactivity of the molecule
19. Which of the following is a consequence of carbon's tetravalency?
A) Formation of only ionic bonds
B) Formation of chains and rings
C) Inability to form multiple bonds
D) Limited to forming only two bonds
20. The shape of a carbanion (e.g., CH₃⁻) is:
A) Linear
B) Trigonal planar
C) Tetrahedral
D) Pyramidal
21. The hybridization of carbon in a carbanion (e.g., CH₃⁻) is typically:
A) sp
B) sp²
C) sp³
D) unhybridized
22. The shape of a carbocation (e.g., CH₃⁺) is:
A) Linear
B) Trigonal planar
C) Tetrahedral
D) Pyramidal
23. The hybridization of carbon in a carbocation (e.g., CH₃⁺) is typically:
A) sp
B) sp²
C) sp³
D) unhybridized
24. The shape of a molecule where a carbon atom is bonded to two other atoms and has no lone pairs is:
A) Linear
B) Trigonal planar
C) Tetrahedral
D) Bent
25. The shape of a molecule where a carbon atom is bonded to three other atoms and has no lone pairs is:
A) Linear
B) Trigonal planar
C) Tetrahedral
D) Pyramidal
26. When a carbon atom forms two double bonds, its hybridization is:
A) sp
B) sp²
C) sp³
D) unhybridized
27. When a carbon atom forms a single bond, a double bond, and a single bond, its hybridization is:
A) sp
B) sp²
C) sp³
D) unhybridized
28. Which type of bond is formed by the overlap of one s orbital and three p orbitals?
A) sp hybridization
B) sp² hybridization
C) sp³ hybridization
D) Sigma bond
29. Which type of bond is formed by the overlap of one s orbital and two p orbitals?
A) sp hybridization
B) sp² hybridization
C) sp³ hybridization
D) Pi bond
30. Which type of bond is formed by the overlap of one s orbital and one p orbital?
A) sp hybridization
B) sp² hybridization
C) sp³ hybridization
D) Sigma bond
31. The hybridization of the carbon atom in a carbonyl group (C=O) is:
A) sp
B) sp²
C) sp³
D) unhybridized
32. In CO₂, the carbon atom is hybridized as:
A) sp
B) sp²
C) sp³
D) unhybridized
33. The shape of the carbon dioxide (CO₂) molecule is:
A) Bent
B) Trigonal planar
C) Linear
D) Tetrahedral
34. In benzene (C₆H₆), each carbon atom is hybridized as:
A) sp
B) sp²
C) sp³
D) dsp²
35. The presence of a triple bond in a molecule indicates that the carbon atoms involved are hybridized as:
A) sp
B) sp²
C) sp³
D) unhybridized
36. The presence of a double bond in a molecule indicates that the carbon atoms involved are hybridized as:
A) sp
B) sp²
C) sp³
D) unhybridized
37. Which of the following carbon atoms undergoes sp hybridization?
A) Carbon in CH₄
B) Carbon in C₂H₄
C) Carbon in CH₃Cl
D) Carbon in C₂H₂
38. Which of the following carbon atoms undergoes sp² hybridization?
A) Carbon in CH₄
B) Carbon in C₂H₆
C) Carbon in C₂H₄
D) Carbon in C₂H₂
39. Which of the following carbon atoms undergoes sp³ hybridization?
A) Carbon in C₂H₂
B) Carbon in C₂H₄
C) Carbon in CH₄
D) Carbon in CO₂
40. The bond angle in ethyne (C₂H₂), where carbon is sp hybridized, is approximately:
A) 90°
B) 109.5°
C) 120°
D) 180°
41. The bond angle in ethene (C₂H₄), where carbon is sp² hybridized, is approximately:
A) 90°
B) 109.5°
C) 120°
D) 180°
42. The bond angle in methane (CH₄), where carbon is sp³ hybridized, is approximately:
A) 90°
B) 109.5°
C) 120°
D) 180°
43. A molecule with sp hybridized carbon atoms will have a geometry that is:
A) Linear
B) Trigonal planar
C) Tetrahedral
D) Bent
44. In ethyne (C₂H₂), each carbon atom is hybridized as:
A) sp
B) sp²
C) sp³
D) sp⁴
45. The shape of a molecule with sp² hybridized carbon atoms is typically:
A) Linear
B) Trigonal planar
C) Tetrahedral
D) Octahedral
46. In ethene (C₂H₄), each carbon atom is hybridized as:
A) sp
B) sp²
C) sp³
D) dsp²
47. A molecule with sp³ hybridized carbon atoms will have a geometry that is:
A) Linear
B) Trigonal planar
C) Tetrahedral
D) Square planar
48. The hybridization of carbon in methane (CH₄) is:
A) sp
B) sp²
C) sp³
D) unhybridized
49. Which type of hybridization is adopted by carbon when it forms four single bonds?
A) sp
B) sp²
C) sp³
D) d²sp³
50. What is the characteristic valency of a carbon atom in organic compounds?
A) Two
B) Three
C) Four
D) One