The C=O double bond has a dipole moment of about 2.4 D and a bond length of about 1.23 Å.
b. Use this information to evaluate the relative importance of the following two resonance contributors:

1. Draw the Lewis structure.

2. Show how the bond dipole moments (and those of any nonbonding pairs of electrons) contribute to the molecular dipole moment.

3. Estimate whether the compound will have a large, small, or zero dipole moment.

d. CH₃F

e. CF₄

f. CH₃OH

Sulfur dioxide has a dipole moment of 1.60 D. Carbon dioxide has a dipole moment of zero, even though C―O bonds are more polar than S―O bonds. Explain this apparent contradiction.

A single bond between two carbons with different hybridizations has a small dipole. What is the direction of the dipole in the indicated bonds?

a.

b.

For each of the following compounds,

1. draw the Lewis structure.

2. show how the bond dipole moments (and those of any nonbonding pairs of electrons) contribute to the molecular dipole moment.

3. estimate whether the compound will have a large, small, or zero dipole moment.

a. CH₃CH=NCH₃

b. CH₃CH₂OH

c. CBr₄

The C≡N triple bond in acetonitrile has a dipole moment of about 3.6 D and a bond length of about 1.16 Å. Calculate the amount of charge separation in this bond. How important is the charge-separated resonance form in the structure of acetonitrile?

For the molecules shown, indicate the direction of the dipole moment.

(b)

For the molecules shown, indicate the direction of the dipole moment.

(a)

Given the Lewis structures, indicate the direction of the dipole moment, if there is one.

(a)