Fluid Mechanics with teacher's notes

Section Review
The ideal gas law
Copyright © by Holt, Rinehart and Winston. All rights reserved.
1. A cylinder with a movable piston contains gas at a temperature of 27°C,
with a volume of 1.5 m 3 and a pressure of 0.20 × 10 5 Pa. What will be the
final temperature of the gas if it is compressed to 0.70 m 3 and its pressure
is increased to 0.80 × 10 5 Pa?
2. Gas is confined in a tank at a pressure of 1.0 × 10 8 Pa and a temperature
of 15.0°C. If half the gas is withdrawn and the temperature is raised to
65.0°C, what is the new pressure in the tank in Pa?
3. A gas bubble with a volume of 0.10 cm 3 is formed at the bottom of a
10.0 cm deep container of mercury. If the temperature is 27°C at the
bottom of the container and 37°C at the top of the container, what is the
volume of the bubble just beneath the surface of the mercury? Assume
that the surface is at atmospheric pressure. (Hint: Use the density of
mercury from Table 9-1.)
1. Name some conditions under which a real gas is likely to behave like an
ideal gas.
2. What happens to the size of a helium balloon as it rises? Why?
3. Two identical cylinders at the same temperature contain the same kind of
gas. If cylinder A contains three times as many gas particles as cylinder B,
what can you say about the relative pressures in the cylinders?
4. The pressure on an ideal gas is cut in half, resulting in a decrease in temperature
to three-fourths the original value. Calculate the ratio of the
final volume to the original volume of the gas.
5. A container of oxygen gas in a chemistry lab room is at a pressure of
6.0 atm and a temperature of 27°C.
a. If the gas is heated at constant volume until the pressure triples, what
is the final temperature?
b. If the gas is heated so that both the pressure and volume are doubled,
what is the final temperature?
PRACTICE 9E
Fluid Mechanics
341
SECTION 9-4
PRACTICE GUIDE 9E
Solving for:
T PE Sample, 1; Ch.
Rvw. 29–30, 45a*
PW 7–9
PB 5–7
P PE 2; Ch. Rvw. 66
PW Sample, 1–3
PB 8–10
V PE 3; Ch. Rvw. 35*,
36*, 40*, 42*,
45b*, 46*
PW 4–6
PB Sample, 1–4
ANSWERS TO
Practice 9E
The ideal gas law
1. 5.6 × 10 2 K
2. 5.9 × 10 7 Pa
3. 1.2 × 10 −7 m 3
Section Review
ANSWERS
1. at relatively high temperature
and relatively low pressure
2. It expands; The air pressure
decreases as altitude increases.
3. The pressure is three times as
great in cylinder A.
4. 3:2
5. a. 9.0 × 10 2 K
b. 1.2 × 10 3 K
341