CHEM 1115 Unit 3 Practice Problems

1. Given the name, write the correct formula. Given the formula, write the correct name.

a. dinitrogen hexoxide

b. P₄O₈

c. aluminum hydroxide

d. hydrogen cyanide

e. AlCl₃

f. hydrochloric acid

g. nitric acid

h. sodium bicarbonate

i. ZnS

j. HClO

k. ammonium carbonate

l. Ag₂O

m. chloric acid

n. sulfur trioxide

o. HNO₃

p. tetraphosphorus heptasulfide

q. Cr₂O₃

r. dinitrogen difluoride

s. S₂F₁₀

t. antimony pentachloride

u. Te₂O₅

v. acetic acid

w. HBr (aq)

x. H₂SO₄

y. magnesium phosphate

z. H₂S (g)

aa. carbonic acid

bb. tetraiodine nonoxide

cc. bromine pentafluoride

dd. ClF

ee. IF₇

ff. perchloric acid

2. Write the Lewis symbol for the following atoms or ions:

a. P

b. S^2-

c. Na

3. Which of the following bonds are polar covalent bonds? Which ones are nonpolar covalent bonds? Which bond is the most polar? Which bond is the most nonpolar?

a. H – H

b. C – H

c. H – F

d. N – H

4. Draw an appropriate Lewis structure for each of the following.

a. NO₂ ^–

b. BrF₃

c. COCl₂

d. ClF₅

e. XeF₂

f. HClO₃

g. N₂O

h. CH₂Br₂

i. N₂O₄ (Hint: The nitrogens are attached to each other. Each nitrogen has two oxygens bonded to it)

5. Draw all possible resonance structures for the SCN^- ion. Calculate the formal charge on each atom for each of the resonance structures. Use the formal charges to determine which of the resonance structures best represents the structure of the ion.

6. For each of the molecules or ions given in problem 4, give the name of the electron domain geometry, the molecular geometry, and sketch each one. In part i, give this information for each of the nitrogen atoms

7. Identify each of the following molecules as a polar molecule or a nonpolar molecule

a. CO₂

b. H₂O

c. CBr₄

d. CO

e. CH₃Cl

f. NH₃

g.

h.