Unit 7 Practice Quiz

NOTE: No assigned e-mail exercises for Unit 7 or Unit 8

Answers for the Practice Quiz will be in the Unit 7 Answer Book

1.a) Dinitrogen oxide, N2O is also called "laughing gas". Three"possible" Lewis structure for N2O are shown in the diagram. Whyis #1 the correct structure ? What is wrong with #2 and #3 ?

2.a) Draw the Lewis structures for nitrogen, N(2) , hydrazine, N2H4 anddinitrogen tetraoxide, N2O4 .

b) On your Lewis structures for these three compounds of nitrogen, discussthe relative bond order and bond length for the "N to N" bondin each one.

3. Draw the Lewis structure for ammonia, NH3 and discuss its VSEPR geometry.What are the approximate H-N-H bond angles in ammonia?

4. Draw Lewis structures and propose appropriate VSEPR geometry for thefollowing: (See structural examples on pages 436 and 438 as a guide)

a) PCl4(+) ion

b) Formaldehyde, HCOH

c) ClF3

d) SCl2

5.Which is the most polar bond ?

a) O-F

b) N-F

c) C-F

d) S-F

e) F-F

6. Draw the three resonance structures for carbonate ion, CO3(2-) andcheck your structures with the ones on page 409.