1. Unit 5 Review
Molecular Compounds

2. 1. When one atom contributes both bonding electrons in a single covalent bond, the bond is called a(n) ____.
A. Ionic bond B. Covalent bond C. Coordinate covalent bond D. Metallic bond

3. 2. The shape of the methane molecule (CH4) is called ____.
A. Linear
B. Trigonal planar
C. Trigonal pyramidal
D. Tetrahedral

4. C. Hydrogen and halogens D. All diatomic molecules
3. Which elements can form diatomic molecules joined by a single covalent bond?
A. Hydrogen only
B. Halogens only
C. Hydrogen and halogens
D. All diatomic molecules

5. 4. Experimental evidence suggests that the H-C-H bond angles in methane, CH4, are ____ degrees.

6. 5. There are 2 identical Lewis structures possible for SO2
5. There are 2 identical Lewis structures possible for SO2. This phenomenon is called
A. Coordinate covalent bond B. Resonance C. Sigma bond D. Electron dot structure

7. 6. CH2F2 is a(n) __________ molecule
A. polar
B. nonpolar
C. ionic
D. metallic

8. A. electrons B. protons C. neutrons D. nuclei
7. According to the VSEPR theory, molecules adjust their shapes to keep ____ as far apart as possible.
A. electrons
B. protons
C. neutrons
D. nuclei

9. 8. What is the shape of a molecule with the formula AB4?
A. Trigonal pyramidal
B. Tetrahedral
C. Bent
D. Straight line

10. A. Polar covalent B. Non-polar covalent C. Ionic bond D. Metallic bond
9. A bond formed between a silicon atom and an oxygen atom is likely to be a(n) ____ bond.
A. Polar covalent
B. Non-polar covalent
C. Ionic bond
D. Metallic bond

11. 10. Which of the following diatomic molecules is joined by a double covalent bond?
A. H2
B. Cl2
C. N2
D. O2

12. 11. Why does carbon show hybridization?
A. To increase the bonding possibilities
B. To increase the number of neutrons
C. To lower the effect of resonance
D. To decrease the number of valence electrons

13. 12. Which of the following covalent bonds is the most polar?
A. H-H
B. H-O
C. N-S
D. H-F

14. 13. What is thought to cause the dispersion forces?
A. The movement of protons.
B. The movement of electrons.
C. Electron transfer.
D. The sharing of electrons.

15. 14. What are the weakest attractions between molecules called?
A. Dispersion forces
B. London dispersion forces
C. Induced dipole forces
D. All of the above

16. 15. Which of the following concerning carbon tetraiodide is correct?
A. Tetrahedral, 109.5, nonpolar
B. Tetrahedral, 109.5, polar
C. Trigonal pyramidal, 107, nonpolar
D. Bent, 104.5, nonpolar

17. 16. What is the shape of a tri-atomic molecule with a triple bond?
A. Straight line
B. Linear
C. Bent
D. Trigonal planar

18. 17. Which of the forces of molecular attraction is the strongest?
Covalent bond
Ionic bond
Dispersion forces
Dipole-dipole forces

19. A. Bonding pairs B. Lone pairs C. Single bond D. Pi bond
18. What is the name given to pairs of valence electrons that do not participate in bonding in diatomic oxygen molecules?
A. Bonding pairs
B. Lone pairs
C. Single bond
D. Pi bond

20. 19. How many covalent bonds are in a covalently bonded molecule containing 1 phosphorus atom and 3 chlorine atoms?
A. 1
B. 2
C. 3
D. 4

21. 20. What is the bond angle in a water molecule?

22. 21. How many unshared pairs of electrons are in a molecule of hydroiodic acid?
B. 1
C. 2
D. 3

23. 22. How many electrons does B need to be stable?8 6 4 2

24. 23. What is shape of a molecule of ammonia (NH3)?
A. Bent
B. Trigonal planar
C. Trigonal pyramidal
D. Tetrahedral

25. 24. What would the bond angle of phosphorus trichloride be?
A. 120 B C. 107 D

26. ANSWERS
1. C 9. A 17. B 2. D 10. D 18. B 3. C 11. A 19. C 4. C 12. D 20. D 5. B 13. B 21. D 6. A 14. D 22. B 7. A 15. A 23. C 8. B 16. B 24. B