Important Questions Collection
Unit One: Chemical Bonding and Shape of Molecules
Chemistry | Science Class 12

Short Questions:

1. Predict the structure of methane based on hybridization. [HSEB 2052]
2. Identify the hybridization of the indicated atom in each of the following molecules. [HSEB 2053]
   i) Be in BeF₂
   ii) B in BF₃
   iii) N in NH₃
3. Draw the shapes of sp and sp² hybrid orbitals. [2056]
4. How do you predict the molecular geometry of NH₃ based on VSEPR model? [HSEB 2057]
5. Draw the orbital picture of ethyne indicating sigma and pi bond. [HSEB 2058]
6. Draw the orbital picture of ethene. [HSEB 2059]
7. How do you interpret that all four C-H bonds of methane are identical. [HSEB 2060]
8. The bond angle is the central atom in NF₃ is 103° where as in BF₃ is 120°. What factor accounts for the difference in bond angles? [HSEB 2061]
9. How do you predict the molecular geometry of NH₃ based on VSEPR model? [HSEB 2061]
10. Define hybridization. Draw the orbital picture of hydrocarbon showing tetrahedral structure. [HSEB 2063]
11. Predict the mode of hybridization in (i) C of C2H4 (ii) B of BF₃. [2065]
12. What is the mode of hybridization of the central atom whose molecular geometry is tetrahedral? And, give an example of it. [HSEB 2066]
13. Mention one examples of each. [HSEB 2067]
    i) Tetrahedral hybridization
    ii) Trigonal hybridization
    iii) Diagonal hybridization
14. Write any two important characters of tetrahedral hybridization. [HSEB 2068]

Long questions:

1. What do you understand by sp² hybridization? Using any example explain the molecular geometry involved. [HSEB 2054]
2. Explain the state of hybridization in ethyne molecule. [HSEB 2055]
3. Using VSEPR theory, explain the shapes of BeF₂ and BF₃. [HSEB 2056]
4. Write short notes on VSEPR theory. [HSEB 2055, 2061]
5. Why is bond angle in: (a) PH₃ is less then NH₃ (b) F₂O is less than H₂O?
6. Explain the state of hybridization in:
   (i) Ethane molecule
   (ii) Ethene molecule
   (iii) Ethyne molecule
   (iv) Methane molecule