CHM20
„
HW-Chapter 1
Name Dang - Key
Due Wednesday 9/7/12
-I'extbook problems:
12,15,17,19,21,25,35,41
Additional problems:
1. Draw a Lewis structure for each of the following species:
a. H2CO
b. CH3NH2
H
°:
||
H
/C H
H ^
I
C
N
H
1!
2. List the bonds in order of decreasing polarity (i.e., list the most polar first)
a. C—O,C—F, C—N
b. H—O, H—N, H—C
C—F > C—O > C—N
H—O > H—N > H—C
3. Predict the approximate bond angles:
a. The C—N—C bond angle in
H3C
N
H
109.5°
b. The H—C—N bond angle in
H y> j
'
v
i. i
109.5°
c. The C—O—C bond angle in CH3OCH3
H3C
CH3
104.5°
similar to H,O
4. Sodium methoxide (CH3ONa) has both ionic and covalent bonds. Which bond is ionic? How many
covalent bonds does it have? (list them out)
The bond between oxygen and sodium is ionic. All the other bonds are covalent.
. Thus, sodium methoxide has 4 covalent bonds.