Chemical Equilibrium
Practice Test
1.
For the reaction, 2NOCl(g) +75 kJ → 2NO(g) + Cl
2
(g), which of the following will shift the reaction to the left?
a.
add a catalyst
b.
add more NOCl
c.
heat the reaction vessel
d.
decrease the volume of the container
2.
For the reaction, 2SO
2
(g) + O
2
(g) → 2SO
3
(g) at equilibrium, the removal of O
2
would cause _______________.
a.
the concentration of SO
2
to decrease, and the concentration of SO
3
to increase
b.
the concentration of SO
2
to decrease, and the concentration of SO
3
to decrease
c.
the concentration of SO
2
to increase, and the concentration of SO
3
to increase
d.
the concentration of SO
2
to increase, and the concentration of SO
3
to decrease
3.
What is the name given to a chemical produced in one elementary step and used up in a subsequent elementary step?
a.
intermediate
b.
elementary step
c.
reaction mechanism
d.
complex step
4.
If 4.27 g sucrose (C
12
H
22
O
11
) are dissolved in 15.2 g water, what is the boiling point of the resulting solution? K
b
for water = 0.512°C/
m
.
a.
101.64°C
b.
99.626°C
c.
100.73°C
d.
100.42°C
5.
How many grams of NaCl are dissolved in 500.0 mL of a 0.05M solution of NaCl?
a.
2.92 g
b.
1.46 g
c.
0.05 g
d.
0.29 g
6.
The process of a solvent and a solute completely mixing and forming a solution is ________.
a.
salvation
b.
solvation
c.
ionization
d.
crystallization
7.
Determine the Celsius temperature of 1.50 moles of ammonia contained in a 10.0-L vessel under a pressure of 2.0 atm.
a.
-111
b.
162°C
c.
-50°C
d.
0.0°C
8.
A gaseous compound is 30.6% nitrogen and 69.4% oxygen by mass. A 5.25-g sample of the gas occupies a volume of 1.00 L and exerts a pressure of 1.26 atm at –4.0°C. What is the molecular formula for the gas?
a.
N
3
O
6
b.
NO
2
c.
N
2
O
4
d.
NO
9.
A colloid contains particles that ____________________.
a.
are atomic-size in scale
b.
are smaller than atoms
c.
settle out if left undisturbed
d.
are between 1 nm and 1000 nm in diameter
10.
Which of the following is not a colligative property?
a.
increasing solubility
b.
freezing point depression
c.
boiling point elevation
d.
vapor pressure lowering
11.
A suspension is _________.
a.
a solution
b.
impossible to prepare
c.
a heterogeneous mixture
d.
a homogeneous mixture
12.
Which of the following is an ionic solid?
a.
nickel
b.
dry ice (solid carbon dioxide)
c.
ammonium chloride
d.
graphite
13.
If NaCl is added to a 0.010M solution of AgNO
3
in water at 25°C, what will be [Cl
-
] when precipitation of AgCl begins? The Ksp for AgCl is 1.8 x 10
-10
.
a.
1.8 x 10
-8
M
b.
1.0 x 10
-10
M
c.
1.8 x 10
-12
M
d.
1.3 x 10
-6
M
14.
For the reaction, 2A + B → C + 2D at 35°C, the value of the forward rate constant,
K
f, is 3.0 × 10
-3
M
-1
s
-1
and the value of the reverse rate constant,
K
r, is 1.5 × 10
-2
M
-2
s
-1
. Calculate the value of
K
eq
for this reaction.
a.
0.5
b.
2
c.
0.2
d.
5
15.
What is the slowest of the elementary steps in a complex reaction called?
a.
fast step
b.
rate-limiting step
c.
mechanism
d.
propagating step
16.
Solutions can be mixtures of _______________.
a.
all of the above
b.
liquids
c.
solids
d.
gases
17.
When will the least time be required for a reaction to reach equilibrium?
a.
K
eq
is very small
b.
K
eq
is approximately 1.00
c.
cannot tell because the time to reach equilibrium does not depend on
K
eq
d.
K
eq
is very large
18.
How many grams of MgF
2
will dissolve in 150 mL of 0.100
M
NaF solution? Ksp for MgF
2
is 6.4 x 10
-9
.
a.
4.1 x 10
-6
g
b.
6.4 x 10
-7
g
c.
6.0 x 10
-6
g
d.
1.0 x 10
-5
g
19.
A solid whose individual particles are arranged in an orderly, geometric, three-dimensional structure is a ___________.
a.
crystalline solid
b.
amorphous solid
c.
liquid crystal
d.
unit cell
20.
How much solvent is needed to make 200 ml of 50% rubbing alcohol?
a.
150 mL
b.
100 mL
c.
200 mL
d.
50 mL
