Name _________________________
CHMA – Lewis Dot Structures of Molecules
In order to understand the covalent bonding in a molecule or polyatomic ion, it is
often useful to draw a Lewis structure of the molecule. In a Lewis structure only the
valence electrons are shown. For anions you will need to add one additional electron for
each negative charge. This electron should usually be given to the most electronegative
atom in the formula. For cations, you will need to remove one electron for each positive
charge. Usually remove the electrons from the least electronegative atom.
Draw Lewis dot structures for the following.
1. HCl
2. H2O
3. Cl2O
4. NH3
5. N2
6. O2
7. HCN
8. CH4
9. C2H2
10. C2H4
11. PCl3
12. C2H6
13. BH4-
14. OF2
© Van Der Sluys, 2004
Name _________________________
CHMA – Lewis Dot Structures of Molecules
15. BF3
16. NH4+
17. CCl4
18. CH3OH
19. H2S
20. ClO-
21. CCl2F2
22. CO2
23. C3H8
24. CH3F
25. CH3CH2OH
26. CH3OCH3
© Van Der Sluys, 2004
Name _________________________
CHMA – Lewis Dot Structures of Molecules
Answers
..
1. H-Cl:
..
2.
..
..
3. :Cl-O-Cl:
..
..
..
H-O-H
..
..
4. H-N-H
H
.. ..
6. :O O:
5. :N N:
H
8. H-C-H
H
7. H-C N:
9. H-C C-H
10. H-C C-H
H H
.. .. ..
11. :Cl-P-Cl:
..
..
:Cl:
..
H H
12. H-C C-H
H H
H
13. H-B-H
H
.. ..
15. :F-B-F:
.. ..
:F:
..
17.
-
.. .. ..
14. :F-O-F:
.. .. ..
H
..
:Cl:
..
..
:Cl-C-Cl:
..
..
:Cl:
..
+
16. H-N-H
H
18.
..
H-C-O-H
..
H
..
19. H-S-H
..
..
:F:
..
..
21. :Cl-C-Cl:
..
..
:F:
..
HHH
23.
H-C-C-C-H
HHH
.. .. 20. [:Cl-O:]
.. ..
H H ..
25. H-C-C-O-H
..
HH
H .. H
26. H-C-O-C-H
..
H H
© Van Der Sluys, 2004
H
..
..
22. :O=C=O:
..
:F:
24. H-C-H
H