Cliffs AP Chemistry, 3rd Edition

12. What is the formal number of pairs of unshared valence electrons in the NO ion 2 +?

A. 0

B. 2

C. 4

D. 8

E. 10

Answer: C

13. The bond energy of BrBr is 192 kJ/mole, and that of ClCl is 243 kJ/mole. What is

the energy of the ClBr bond?

A. 54.5 kJ/mole

B. 109 kJ/mole

C. 218 kJ/mole

D. 435 kJ/mole

E. 870 kJ/mole

Answer: C

If the polarity of the bond AB is about the same as those of the nonpolar bonds AA and
BB, then the bond energy of AB can be taken as the average of the bond energies of AA
and BB.

O N O

Part II: Specific Topics