Gases
Practice Test
1.
Calculate the number of moles of gas contained in a 16.0-L vessel at 373 K with a pressure of 2.50 atm.
a.
2.8 x 10
-3
mol
b.
1.31 x 10
-1
mol
c.
1.31 mol
d.
0.766 mol
2.
The theory that describes the behavior of gases in terms of the motion of gas particles is _____________.
a.
the kinetic-molecular theory
b.
Dalton’s law of parhal pressures
c.
Graham’s law of effusion
d.
the theory of intermolecular forces
3.
What is the maximum amount of Ca
3
(PO
4
)
2
that can be prepared from 9.8 grams of Ca(OH)
2
and 9.8 grams of H
3
PO
4
?
3Ca(OH)
2
+ 2H
3
PO
4
→ Ca
3
(PO
4
)
2
+ 6H
2
O
a.
6.8 g
b.
8.6 g
c.
10.3 g
d.
13 g
4.
What will happen to a real gas when the temperature is lowered and the pressure is raised?
a.
The gas does not change.
b.
The gas eventually condenses to become a liquid.
c.
The number of gas particles doubles.
d.
The gas expands.
5.
A 0.5-L container of nitrogen gas is heated under constant pressure to the boiling point of water. What is its new volume?
a.
0.79 L
b.
0.86 L
c.
0.64 L
d.
0.5 L
6.
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What volume will 0.554 mol of gas occupy at STP?
a.
40.4 L
b.
0.25 L
c.
12.4 L
d.
3.34 L
7.
How can gases be defined?
a.
a physical state of matter that does not have a fixed shape or a fixed volume
b.
a chemical state of matter
c.
a physical state of matter that does not have a fixed shape but has a fixed volume
d.
a physical state of matter that has a fixed volume and a fixed shape
8.
How many moles of sulfur are present in 5 moles of H
2
SO
4
?
a.
1 mol
b.
5 mol
c.
10 mol
d.
2 mol
9.
Determine the number of atoms in 3.54 mol S.
a.
1.70 x 10
24
b.
2.13 x 10
23
c.
1.70 x 10
23
d.
2.13 x 10
24
10.
What mass of SrF
2
can be prepared from the reaction of 10.0 g Sr(OH)
2
with excess HF?
Sr(OH)
2
+ 2HF → SrF
2
+ 2H
2
O
a.
9.82 g
b.
9.67 g
c.
10.3 g
d.
10.0 g
11.
Balance the following equation with the smallest whole—number coefficients. How many moles of Ag
2
S can be prepared from 3 moles of Ag?
Ag + H
2
S + O
2
→ Ag
2
S + H
2
O
a.
4.0 mol
b.
1.5 mol
c.
2.0 mol
d.
1.0 mol
12.
One atmosphere is equal to ____________.
a.
1 mm Hg
b.
760 mm Hg
c.
1 cm Hg
d.
760 cm Hg
13.
How can the molar volume of a gas be defined?
a.
the volume that one mole occupies at 100°C and 1 atm pressure
b.
the volume that one mole occupies at STP
c.
the volume that one gram occupies at STP
d.
the volume that one gram occupies at 100°C and 1 atm pressure
14.
How many moles of HCl will just react with 0.424 g Ba(OH)
2
?
2HCl + Ba(OH)
2
→ BaCl
2
+ 2H
2
O
a.
9.90 x 10
-3
mol
b.
1.24 x10
-3
mol
c.
4.94 x 10
-3
mol
d.
2.48 x 10
-3
mol
15.
What is the SI base unit used to measure the amount of a substance?
a.
kilogram
b.
kelvin
c.
meter
d.
mole
16.
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°C
b.
0.0°C
c.
162°C
d.
-50°C
17.
What is the ratio between the coefficients of any two substances in a balanced equation?
a.
mole ratio
b.
molar mass balanced equation
c.
chemical formula
d.
quadratic equation
18.
A 10.0-L vessel contains gas A at a pressure of 300.0 torr. A 3.00-L vessel contains gas B at a pressure of 400.0 torr. Gas A is forced into the second vessel. Calculate the resulting pressure in torr. Assume the temperature remains constant.
a.
1400 torr
b.
1800 torr
c.
2000 torr
d.
1000 torr
19.
What is the maximum amount of product that can be produced from a given amount of reactant?
a.
percent yield
b.
actual yield
c.
mole ratio
d.
theoretical yield
20.
What is the percent yield for the reaction between 9.8 grams of Ca(OH)
2
and 9.8 grams of H
3
PO
4
when 2.5 grams of
Ca
3
(PO
4
)
2
are actually obtained?
3Ca(OH)
2
+ 2H
3
PO
4
→ Ca
3
(PO
4
)
2
+ 6H
2O
a.
9%
b.
27%
c.
19%
d.
36%
