Name: ___________________________________ Block: _______________ Date: ___________________
Unit 9: Gases
Practice Test
Objective 1: Describe gases in terms of their observable properties and behavior of their particles.
Determine whether the statements about the observable properties of gases are TRUE (T) or FALSE (F)
___ 1.
Gases can be compressed.
___ 2.
Gases have high densities.
___ 3.
Gases spontaneously move from an area of high concentration to an area of low concentration.
Determine whether the statements below are TRUE (T) or FALSE (F) according to the Kinetic Molecular Theory.
___ 4.
Gas particles are in constant, random motion.
___ 5.
An increase in temperature of a gas has no effect on the speed of its molecules.
___ 6.
Which choice best represents standard pressure?
A) 1.00 kPa
___ 7.
B) 760 atm
C) 760 mm Hg
D) 101.3 torr
What temperature in °C is equivalent to 198K?
___ 8.
The total pressure of a mixture of Ar, N2, and O2 gases is 725 torr. The partial pressure of argon is 250
torr and the pressure exerted by oxygen gas is 175 torr. What is the pressure exerted by nitrogen?
___ 9.
Score box
What pressure, in kPa, does a gas exert at 658 torr? (include WORK, SIG FIGS, and UNITS)
□ A= 9/9 (100)
□ B= 8/9 (89)
□ NY
Name: ___________________________________ Block: _______________ Date: ___________________
Objective 2: Use the Combined Gas Law to calculate initial and final P, V, and T.
Directions: Solve the following problems, including all WORK and UNITS, and SIG FIGS. Place a BOX around
your final answer.
1. A high-altitude balloon contains 10.0 Liters of helium gas at 235.0 kPa. What is the volume when the balloon
rises to an altitude where the pressure is only 100.0 kPa? Assume that the temperature remains constant. [2]
2. If a sample of gas occupies 16.4 Liters at ‒55oC, what will be its volume at 16oC if the pressure does not change?
[2]
3. A gas at 1.90 kPa and 418 K occupies a container with an initial volume of 20.0 Liters. By changing the volume,
the pressure of the gas increases to 25.0 kPa as the temperature is raised to 468 K. What is the new volume? [2]
4. A researcher takes a sample of gas at 350 mm Hg and 135oC and brings the gas to STP, where its new volume is
3.96 L. What was the original volume of the gas? [2]
5. Which of the following graphs best represents the temperature-volume relationship of a gas at constant pressure?
Score box
□ A= 9/9 (100)
□ B= 8/9 (89)
□ NY
Name: ___________________________________ Block: _______________ Date: ___________________
Objective 3: Apply the Ideal Gas Law to problems involving pressure, volume and temperature.
1. State the Ideal Gas Law (the equation).
2. What value of R should be used if the pressure is given in torr? ______________________
3. Under which conditions will a gas behave most ideally?
A)
B)
500oC and 15.0 atm
100oC and 1.0 atm
C)
D)
500oC and 1.0 atm
100oC and 15.0 atm
4. Assuming equal temperatures and pressures, which gas below will demonstrate the most ideal behavior?
A) H2O
B) He
C) SO2
D) CH4
Directions: Solve the following problems, including all WORK, UNITS, and SIG FIGS. Place a BOX around your
final answer.
5. You fill a rigid steel cylinder that has a volume of 4.5 L with oxygen gas to a final pressure of 3.0 atm. How many
moles of gas does the cylinder contain at 25oC? [2]
6. What volume will 40.7 grams of krypton gas occupy at 208oC and a pressure of 233 kPa? [2]
Name: ___________________________________ Block: _______________ Date: ___________________
Score box
□ A= 9/9 (100)
□ B= 8/9 (89)
□ NY