Cliffs AP Chemistry, 3rd Edition

5. What is the geometry of the hydronium ion, H 3 O+?

Answer: C

6. Which one of the following is a nonpolar molecule with one or more polar bonds?

A. HBr

B. ClBeCl

C. HH

D. HOH

E. KCl

Answer: B

A.

B.

C.

D.

E. Compound is ionic,

The Cl atom is more electronegative than the Be atom, resulting in a polar bond. However, be-
cause the molecule is linear and the two ends are identical, the overall molecule is nonpolar.

7. How many total sigma bonds are in the benzene molecule, C 6 H 6?

A. 6

B. 9

C. 12

D. 14

E. 18

Answer: C

All single bonds are sigma (σ) in nature. Double bonds contain one sigma bond and one pi (π)
bond. Triple bonds contain one sigma bond and two pi (π)bonds.

Cl

−

K

+

O

H H

HH

Cl Be Cl

H Br

H O H

H

+

Covalent Bonding