C
HAPTER
10
Gases and the Atmosphere
201
Objectives
You will be able to:
1.
For a typical gas, state the percentage of space inside a gas-filled container that is
occupied by the gas particles themselves.
2.
State the average distance traveled between collisions by oxygen molecules, O
2
, at
normal room temperature and pressure.
3.
Write the key assumptions that distinguish an ideal gas from a real gas.
4.
Describe the process that gives rise to gas pressure.
5.
State the accepted SI unit for gas pressure.
6.
Convert between the names and abbreviations for the following pressure units:
pascal (Pa), atmosphere (atm), millimeter of mercury (mmHg), and torr.
7.
Convert a gas pressure described in pascals (Pa), atmospheres (atm), millimeters
of mercury (mmHg), or torr to any of the other units.
8.
Convert between the names and variables used to describe pressure (
P
),
temperature, (
T
), volume (
V
), and moles of gas (
n
).
9.
For each of the following pairs of gas properties, (1) describe the relationship
between the properties, (2) describe a simple system that could be used to
demonstrate the relationship, and (3) explain the reason for the relationship:
(a) volume and pressure when moles of gas and temperature are constant, (b)
pressure and temperature when volume and moles of gas are constant, (c) volume
and temperature when pressure and moles of gas are constant, (d) moles of gas
and pressure when volume and temperature are constant, and (e) moles of gas
and volume when pressure and temperature are constant
10. Explain why decreased volume for the gasoline air mixture in the cylinders of a
gasoline engine, increased number of moles of gas, and increased temperature
lead to an increase in pressure in the cylinders.
11. Explain why air moves in and out of our lungs as we breathe.
12. Explain why balloons expand as they rise into the atmosphere.
13. Write at least one value for the universal gas constant, R, including units.
14. Given values for three of the following four variables, calculate the fourth:
P
,
V
,
n
, and
T
.
15. Given values for four out of the following five variables, calculate the fifth:
P
,
V
,
g, M, and
T
.
16. Given the pressure and temperature of a gas, calculate its density.
17. Given (directly or indirectly) values for seven out of the following eight variables,
calculate the eighth:
P
1
,
V
1
,
n
1
,
T
1
,
P
2
,
V
2
,
n
2
, and
T
2
.
18. Convert between volume of gas and moles of gas in an equation stoichiometry
problem using either the molar volume at STP, the ideal gas equation, or
R
as a
conversion factor.
19. Explain why the total pressure of a mixture of ideal gases is equal to the sum of
the partial pressures of each gas.
20. Given all but one of the following properties for a mixture of gases, calculate the
one not given: total pressure of the mixture of gases and partial pressure of each
gas.