CHEM 103 — Module 5: Gases, Gas Laws, and Kinetic Molecular
Theory 2026/2027 UPDATE
1. Which of the following units is equivalent to 1 millimeter of mercury (1
mmHg)?
A. 1 torr
B. 1 Pascal
C. 1 atmosphere
D. 1 bar
Answer: A
Rationale: By definition, 1 mmHg is equal to 1 torr. 760 mmHg or 760 torr equals 1
atmosphere.
2. Boyle’s Law states that for a fixed amount of gas at constant temperature,
the volume of the gas is:
A. Directly proportional to the pressure
B. Independent of the pressure
C. Directly proportional to the Kelvin temperature
D. Inversely proportional to the pressure
Answer: D
Rationale: Boyle’s Law (P1V1 = P2V2) states that pressure and volume are inversely
proportional when temperature and moles are constant.
,3. What is the standard temperature and pressure (STP) for gases?
A. 273.15 K and 1 atm
B. 0 K and 1 atm
C. 25°C and 1 atm
D. 100°C and 760 torr
Answer: A
Rationale: STP is defined as a temperature of 0°C (273.15 K) and a pressure of 1
atmosphere (760 mmHg).
4. Which gas law relates the volume and temperature of a gas at constant
pressure?
A. Boyle’s Law
B. Dalton’s Law
C. Avogadro’s Law
D. Charles’s Law
Answer: D
Rationale: Charles’s Law states that volume is directly proportional to the absolute
temperature (in Kelvin) when pressure is held constant.
5. A sample of gas occupies 2.0 L at 300 K. If the temperature is increased to 600
K at constant pressure, what will the new volume be?
A. 1.0 L
B. 8.0 L
C. 2.0 L
D. 4.0 L
Answer: D
Rationale: According to Charles’s Law (V1/T1 = V2/T2), if the absolute temperature
doubles, the volume also doubles (2.0 L * 2 = 4.0 L).
, 6. What is the volume of 1.00 mole of an ideal gas at STP?
A. 24.5 L
B. 22.4 L
C. 1.00 L
D. 11.2 L
Answer: B
Rationale: Molar volume of an ideal gas at STP (0°C, 1 atm) is 22.414 L/mol.
7. Which of the following is NOT a postulate of the Kinetic Molecular Theory?
A. Gas particles are in constant, random motion
B. Gas particles exert strong attractive forces on each other
C. The volume of individual gas particles is negligible
D. Collisions between gas particles are perfectly elastic
Answer: B
Rationale: KMT assumes there are no attractive or repulsive forces between gas particles
in an ideal gas.
8. The pressure of a gas is 760 mmHg. What is this pressure in kPa?
A. 1.00 kPa
B. 14.7 kPa
C. 101.3 kPa
D. 760 kPa
Answer: C
Rationale: 1 atmosphere = 760 mmHg = 101.325 kPa.
Theory 2026/2027 UPDATE
1. Which of the following units is equivalent to 1 millimeter of mercury (1
mmHg)?
A. 1 torr
B. 1 Pascal
C. 1 atmosphere
D. 1 bar
Answer: A
Rationale: By definition, 1 mmHg is equal to 1 torr. 760 mmHg or 760 torr equals 1
atmosphere.
2. Boyle’s Law states that for a fixed amount of gas at constant temperature,
the volume of the gas is:
A. Directly proportional to the pressure
B. Independent of the pressure
C. Directly proportional to the Kelvin temperature
D. Inversely proportional to the pressure
Answer: D
Rationale: Boyle’s Law (P1V1 = P2V2) states that pressure and volume are inversely
proportional when temperature and moles are constant.
,3. What is the standard temperature and pressure (STP) for gases?
A. 273.15 K and 1 atm
B. 0 K and 1 atm
C. 25°C and 1 atm
D. 100°C and 760 torr
Answer: A
Rationale: STP is defined as a temperature of 0°C (273.15 K) and a pressure of 1
atmosphere (760 mmHg).
4. Which gas law relates the volume and temperature of a gas at constant
pressure?
A. Boyle’s Law
B. Dalton’s Law
C. Avogadro’s Law
D. Charles’s Law
Answer: D
Rationale: Charles’s Law states that volume is directly proportional to the absolute
temperature (in Kelvin) when pressure is held constant.
5. A sample of gas occupies 2.0 L at 300 K. If the temperature is increased to 600
K at constant pressure, what will the new volume be?
A. 1.0 L
B. 8.0 L
C. 2.0 L
D. 4.0 L
Answer: D
Rationale: According to Charles’s Law (V1/T1 = V2/T2), if the absolute temperature
doubles, the volume also doubles (2.0 L * 2 = 4.0 L).
, 6. What is the volume of 1.00 mole of an ideal gas at STP?
A. 24.5 L
B. 22.4 L
C. 1.00 L
D. 11.2 L
Answer: B
Rationale: Molar volume of an ideal gas at STP (0°C, 1 atm) is 22.414 L/mol.
7. Which of the following is NOT a postulate of the Kinetic Molecular Theory?
A. Gas particles are in constant, random motion
B. Gas particles exert strong attractive forces on each other
C. The volume of individual gas particles is negligible
D. Collisions between gas particles are perfectly elastic
Answer: B
Rationale: KMT assumes there are no attractive or repulsive forces between gas particles
in an ideal gas.
8. The pressure of a gas is 760 mmHg. What is this pressure in kPa?
A. 1.00 kPa
B. 14.7 kPa
C. 101.3 kPa
D. 760 kPa
Answer: C
Rationale: 1 atmosphere = 760 mmHg = 101.325 kPa.
