1. On the basis of the VSEPR model, which of the following molecules is linear?
   1. H₂O
   2. BF₃
   3. BeF₂
   4. CH₄
   5. none of these

2. The molecular shape of H₃O⁺ is:
   1. linear.
   2. planar.
   3. see-saw.
   4. trigonal planar.
   5. trigonal pyramidal.

3. Which of the following is a planar molecule or ion?
   

4. Which of the following molecules or ions is not linear?
   
   The next three questions refer to the molecule OXeF4 with a Lewis dot structure shown below.
   

5. The formal charge on the Xe atom is:
   1. -2
   2. -1
   3. 0
   4. +1
   5. +2

6. The geometry of the OXeF₄ molecule is:
   1. trigonal bipyramidal.
   2. octahedral.
   3. square pyramidal.
   4. square planar.
   5. none of the above.

7. The number of bonding pair-to-bonding pair repulsions in OXeF₄ is:
   1. 0
   2. 2
   3. 4
   4. 8
   5. 12

8. The molecular shape of SeF₄ is:
   1. see-saw.
   2. square planar.
   3. tetrahedral.
   4. square pyramidal.
   5. impossible to predict.

9. Which of the following hybrid orbitals forms bond angles of approximately 109^o?
   1. sp
   2. sp²
   3. sp³
   4. sp³d
   5. sp³d²

10. When the molecules H₂O, CH₄, and NH₃ are arranged in order of increasing bond angle, the correct sequence is:
    1. H₂O, CH₄, NH₃
    2. H₂O, NH₃, CH₄
    3. NH₃, H₂O, CH₄
    4. CH₄, NH₃, H₂O
    5. CH₄, H₂O, NH₃

11. Which of the following molecules has the smallest angle between adjacent bonds?
    1. CO₂
    2. CH₄
    3. H₂O
    4. NH₃
    5. PH₃

12. The shape of ICl₄^- is:
    1. octahedral.
    2. see saw.
    3. square planar.
    4. tetrahedral.
    5. square pyramidal.

13. What are the approximate values of the bond angles, a and b, in the ion illustrated below?
    
    1. a is ~90^o and b is ~90^o
    2. a is ~109^o and b is ~109^o
    3. a is ~109^o and b is ~120^o
    4. a is ~120^o and b is ~109^o
    5. a is ~90^o and b is ~180^o

14. The molecules NF₃, BF₃, and ClF₃ have similar molecular formulas but different molecular geometries. Use VSEPR to predict their molecular shapes.
    1. NF₃ trigonal pyramidal; BF₃ trigonal planar; ClF₃ T-shaped
    2. NF₃ T-shaped; BF₃ trigonal planar; ClF₃ trigonal pyramidal
    3. NF₃ trigonal planar; BF₃ T-shaped; ClF₃ trigonal pyramidal
    4. NF₃ T-shaped; BF₃ trigonal pyramidal; ClF₃ trigonal planar
    5. NF₃ trigonal pyramidal; BF₃ T-shaped; ClF₃ trigonal planar

15. Which of the following best describes the shape and polarity of the carbon disulfide, CS₂, molecule?
    1. bent and polar
    2. linear and non-polar
    3. pyramidal and polar
    4. bent and non-polar
    5. linear and polar

16. The shape of XeF₄ is:
    1. tetrahedral.
    2. see-saw.
    3. square pyramidal.
    4. trigonal pyramidal.
    5. square planar.

17. Which of the following molecules or ions is nonplanar, i.e., has at least one atom that is not in the same plane as the others?
    1. BH₃
    2. ClF₃
    3. NF₃
    4. SO₃
    5. CO₃^2-

18. On the basis of the VSEPR model, which of the following triatomic molecules has the smallest angle between the two bonds?
    1. CO₂
    2. H₂O
    3. SO₂
    4. O₃
    5. CH₄

19. For the amino acid alanine, what is the bond angle about the indicated carbon atom?
    
    1. 109.5^o
    2. 120^o
    3. 180^o
    4. 90^o
    5. 360^o

20. Identify the molecular geometry of formaldehyde, CH₂O.
    1. linear
    2. trigonal planar
    3. bent
    4. tetrahedral
    5. trigonal bipyramidal

Answers

1. C
2. E
3. E
4. B
5. D
6. C
7. D
8. A
9. C
10. B
11. C
12. C
13. C
14. A
15. B
16. E
17. C
18. B
19. A
20. B