Chemistry Final Exam Review # 3
Chapter 12: Chemical Bonding
Define the following terms: Bond, ionic bonding, ionic compound, covalent bonding, nonpolar
covalent bond, polar covalent bond, electronegativity, dipole moment, Lewis structure, octet
rule, bonding pair, lone pair (unshared pair), single bond, double bond, triple bond, Valence
shell electron pair repulsion theory (VSEPR), tetrahedral structure, Pyramidal structure, bent
structure, trigonal planar structure, linear structure
Questions:
1. How are ionic bonds and covalent bonds different?
Ionic bonds involve a transfer of electrons between atoms, while covalent bonds involve a
sharing of electrons between atoms. Ionic bonds usually occur between a metal and a nonmetal,
while covalent bonds occur between nonmetals.
2. How is a polar covalent bond different from a nonpolar covalent bond?
In polar covalent bonds, the electrons are not shared equally. The bonding electrons are
closer to the atom with the higher electronegativity. Nonpolar covalent bonds involve equal
sharing of electrons
3. For each of the following sets of elements, place the elements in order of increasing
electronegativity.
a. K, Sc, Ca
K, Ca, Sc
b. Br, F, At
At, Br, F
c. C, O, N
C, N, O
4. What type of ion do oxygen atoms typically form and why? (Hint: Consider oxygen’s
electron configuration.)
Oxygen atoms typically form ions with a charge of –2 (O-2). Oxygen gains two electrons to
become an ion in order to fill its outer energy level with electrons. In its electron configuration,
1s22s22p4, two additional electrons will fill the 2nd energy level.
5. Predict the formula for an ionic compound formed from each pair of elements.
a. Mg, S
MgS
b. K, Cl
KCl
c. Cs, F
CsF
d. Ba, Br
BaBr2
6. For each of the following molecules, draw the Lewis dot structure, list the molecular
shape, and give the bond angles.
a. CCl4
tetrahedral, 109.5o
b. PH3
pyramidal, 107o
c. N2
linear
d. SCN-1 (Carbon is the central atom)
linear, 180o
e. H2S
bent, 105o
f. C2H2F2
trigonal planar, 120o
··
H:S:H
··
g. CH3OCH3
i. NH4+1
tetrahedral, bent
109.5o, 105o
h. CO2
tetrahedral, 109.5o
J. H2O
O H
H
linear, 180o
bent, 105o
Chapter 13: Gases
Define the following terms: Pressure, barometer, manometer, standard atmospheric pressure,
Kinetic molecular theory, Boyle’s Law, Charles’ Law, absolute zero, Avogadro’s Law, GayLussac’s Law, universal gas constant, ideal gas law, ideal gas, combined gas law, Dalton’s Law
of Partial Pressures, Molar volume, standard temperature and pressure (STP)
1. List the components of the kinetic molecular theory of gases.
 Gases are made of tiny particles that have mass
 Gases are spread very far apart from each other
 Gases particles are in constant motion
 As a result of constant motion gas particles collide with each other and the walls of
their container, thus, exerting pressure on their surroundings
 Temperature is a measure of the average kinetic energy of the particles of a gas
 Gas particles do not exert and force on each other except for when they collide
Use the kinetic molecular theory to answer each of the following questions. Be sure to base
your answer upon the behavior of gas particles.
2. Describe in terms of gas particles, how wind allows a sailboat to be propelled through the
water.
Wind is composed of air particles in motion. Because those particles have mass, they exert a
force when they collide with the sail on a sailboat. That force pushes the boat through the
water.
3. Explain why an air mattress provides a soft, cushioned surface to sleep on.
The air particles contained in an air mattress are very far apart. As a result, it is easy for the
particles to be pushed closer together as a person lies on the mattress.
4. Explain why odors travel quickly throughout a room.
Odors travel quickly throughout a room because of the fact that gas particles move very
quickly. They are also spread far apart from each other, so it is easy for gases to mix
together.
5. Explain what happens if the volume of a container of gas decreases.
If the volume of a container decreases, the gas particles will have less room to move around.
As a result, there will be more collisions and, therefore, higher pressure.
6. Explain why there are warnings on gas tanks that warn against exposure to high
temperatures.
At high temperatures, the gas particles will be moving faster. This leads to more frequent
collisions and collisions with greater force. As a result, the pressure will increase. The
danger is due to the fact that, at high pressures, it is possible for the tank to rupture.
Problems:
7. Automobile tires should be inflated to a pressure of 35 psi. Convert this pressure into
units of mm Hg.
14.69 psi = 760 mm Hg


35 psi  760 mm Hg   1800 mm Hg
 14.69 psi 
8. A sample of neon gas measures 1.51 L with a pressure of 635 mm Hg. If the gas sample
is added to a new container and the pressure is measured to be 785 mm Hg, calculate the
volume of the new container.
(1.51 L)(635 mm Hg) = (785 mm Hg)(V2)
V2 = 1.22 L
9. A balloon has a volume of 23 cm3 at a temperature of 28oC. What will the balloon’s
volume be if it is placed outside where the temperature is 18oC?
V2
23 cm 3

28C  273 18C  273
V2 = 22.2 cm3
10. A sample of argon gas with a volume of 11.0 L at a temperature of 13oC and a pressure of
0.747 atm is heated to 56oC and a pressure of 1.18 atm. Calculate the final volume.
0.747 atm11.0 L  1.18 atmV2 
13C  273
56C  273
V2 = 8.01 L
11. Consider two samples of nitrogen gas. Sample 1 contains 1.5 moles of N2 and has a
volume of 36.7 L at 25oC and 1 atm. Sample 2 has a volume of 16.5 L at the same
temperature and pressure. Calculate the number of moles of N2 in Sample 2.
36.7 L 16.5 L

n2 = 0.67 moles
1.5 mol
n2
12. Radon is a radioactive gas found to occur naturally in soil. What will the pressure of a
sample of radon be if a 1.5 mole sample of the gas has a volume of 21.0 L at 33oC?
(P)(21.0 L) = (1.5 moles)(0.0821 L*atm/mol*K)(33oC + 273)
P = 1.8 atm
13. A sample of hydrogen gas is collected over water where the vapor pressure of water is 24
mm Hg. If the total pressure is 722 mm Hg, calculate the partial pressure of hydrogen.
(Dalton’s law of partial pressure)
722 mm Hg = 24 mm Hg + PH2
PH2 = 698 mm Hg
14. A sample of argon gas has a volume of 3.45 L at STP. What is the mass of the argon?
(Hint: Convert the volume into moles, then convert moles to grams.)



3.45 L 1mole Ar  39.95 g Ar   6.15 g Ar
 22.4 L Ar  1 mole Ar 
15. When magnesium reacts with hydrochloric acid, hydrogen gas is produced:
Mg + 2 HCl  MgCl2 + H2 (g)
Calculate the volume of hydrogen gas produced at STP by reacting 5.00 g of Mg and an
excess of HCl.
 1 mol Mg  1 mol H 2  22.4 L H 2 
  4.61 L H 2


24
.
31
g
Mg
1
mol
Mg
1
mol
H



2 
5.00 g Mg 