CHEM 120 Week 4 Lab Report 4 Ideal Gas
Law 200 Multiple Choice Questions with
Verified Answers and Rationales for
Chemistry Lab Success Graded A+
1. Which equation represents the Ideal Gas Law?
A. P = nRT
B. PV = nRT
C. V = PRT
D. PT = nRV
Answer: B
Rationale: The Ideal Gas Law relates pressure, volume, amount of gas, and absolute
temperature as PV = nRT.
2. What does P represent in PV = nRT?
A. Power
B. Pressure
C. Partial volume
D. Potential energy
Answer: B
Rationale: P represents pressure.
3. What does V represent?
A. Volume
B. Velocity
C. Vapor pressure
D. Voltage
Answer: A
Rationale: V represents gas volume.
4. What does n represent?
A. Number of molecules only
B. Moles of gas
,C. Newtons
D. Density
Answer: B
Rationale: n is the amount of gas measured in moles.
5. What does T represent in the Ideal Gas Law?
A. Time
B. Temperature in Celsius
C. Absolute temperature
D. Pressure
Answer: C
Rationale: Temperature must be expressed on an absolute scale, normally Kelvin.
6. Why must temperature be converted to Kelvin for gas-law calculations?
A. Kelvin is always smaller than Celsius
B. Gas-law relationships use absolute temperature
C. Celsius cannot be measured
D. Kelvin eliminates pressure
Answer: B
Rationale: Kelvin begins at absolute zero, making it appropriate for proportional gas-law
relationships.
7. What is 25°C in Kelvin?
A. 248 K
B. 273 K
C. 298 K
D. 325 K
Answer: C
Rationale: K = °C + 273.15, so 25°C ≈ 298 K.
8. What is 0°C approximately equal to?
A. 0 K
B. 100 K
C. 273 K
D. 373 K
Answer: C
Rationale: 0°C corresponds to approximately 273.15 K.
,9. Which gas constant is commonly used with pressure in atm and volume in liters?
A. 8.314 L·kPa/mol·K
B. 0.08206 L·atm/mol·K
C. 62.36 L·mmHg/mol·K
D. 1.987 cal/mol·K
Answer: B
Rationale: 0.08206 L·atm·mol⁻¹·K⁻¹ matches liters and atmospheres.
10. What unit should temperature have when using the Ideal Gas Law?
A. °C
B. °F
C. K
D. °R only
Answer: C
Rationale: Absolute temperature in Kelvin is required.
11. If pressure increases while temperature and moles remain constant, what happens to
volume?
A. It increases
B. It decreases
C. It remains unchanged
D. It becomes zero
Answer: B
Rationale: Pressure and volume are inversely proportional at constant temperature and amount
of gas.
12. If volume increases while temperature and moles remain constant, pressure will:
A. Increase
B. Decrease
C. Remain constant
D. Become negative
Answer: B
Rationale: Increasing volume decreases pressure when other variables remain constant.
13. If temperature increases at constant pressure and moles, volume will:
A. Increase
B. Decrease
, C. Remain constant
D. Become negative
Answer: A
Rationale: Volume is directly proportional to absolute temperature at constant pressure.
14. Which law describes the inverse relationship between pressure and volume?
A. Charles's Law
B. Boyle's Law
C. Avogadro's Law
D. Dalton's Law
Answer: B
Rationale: Boyle's Law states that pressure and volume are inversely related at constant
temperature and amount of gas.
15. Which law describes the relationship between volume and absolute temperature?
A. Boyle's Law
B. Charles's Law
C. Dalton's Law
D. Graham's Law
Answer: B
Rationale: Charles's Law states that V/T is constant at constant pressure and amount of gas.
16. Which law relates volume and moles at constant pressure and temperature?
A. Avogadro's Law
B. Boyle's Law
C. Charles's Law
D. Dalton's Law
Answer: A
Rationale: Avogadro's Law states that volume is directly proportional to the number of moles.
17. A gas occupies 2.0 L at 1.0 atm. If pressure doubles at constant temperature, what is the
new volume?
A. 0.5 L
B. 1.0 L
C. 2.0 L
D. 4.0 L
Answer: B
Rationale: Boyle's Law gives P₁V₁ = P₂V₂. Doubling pressure halves volume.
Law 200 Multiple Choice Questions with
Verified Answers and Rationales for
Chemistry Lab Success Graded A+
1. Which equation represents the Ideal Gas Law?
A. P = nRT
B. PV = nRT
C. V = PRT
D. PT = nRV
Answer: B
Rationale: The Ideal Gas Law relates pressure, volume, amount of gas, and absolute
temperature as PV = nRT.
2. What does P represent in PV = nRT?
A. Power
B. Pressure
C. Partial volume
D. Potential energy
Answer: B
Rationale: P represents pressure.
3. What does V represent?
A. Volume
B. Velocity
C. Vapor pressure
D. Voltage
Answer: A
Rationale: V represents gas volume.
4. What does n represent?
A. Number of molecules only
B. Moles of gas
,C. Newtons
D. Density
Answer: B
Rationale: n is the amount of gas measured in moles.
5. What does T represent in the Ideal Gas Law?
A. Time
B. Temperature in Celsius
C. Absolute temperature
D. Pressure
Answer: C
Rationale: Temperature must be expressed on an absolute scale, normally Kelvin.
6. Why must temperature be converted to Kelvin for gas-law calculations?
A. Kelvin is always smaller than Celsius
B. Gas-law relationships use absolute temperature
C. Celsius cannot be measured
D. Kelvin eliminates pressure
Answer: B
Rationale: Kelvin begins at absolute zero, making it appropriate for proportional gas-law
relationships.
7. What is 25°C in Kelvin?
A. 248 K
B. 273 K
C. 298 K
D. 325 K
Answer: C
Rationale: K = °C + 273.15, so 25°C ≈ 298 K.
8. What is 0°C approximately equal to?
A. 0 K
B. 100 K
C. 273 K
D. 373 K
Answer: C
Rationale: 0°C corresponds to approximately 273.15 K.
,9. Which gas constant is commonly used with pressure in atm and volume in liters?
A. 8.314 L·kPa/mol·K
B. 0.08206 L·atm/mol·K
C. 62.36 L·mmHg/mol·K
D. 1.987 cal/mol·K
Answer: B
Rationale: 0.08206 L·atm·mol⁻¹·K⁻¹ matches liters and atmospheres.
10. What unit should temperature have when using the Ideal Gas Law?
A. °C
B. °F
C. K
D. °R only
Answer: C
Rationale: Absolute temperature in Kelvin is required.
11. If pressure increases while temperature and moles remain constant, what happens to
volume?
A. It increases
B. It decreases
C. It remains unchanged
D. It becomes zero
Answer: B
Rationale: Pressure and volume are inversely proportional at constant temperature and amount
of gas.
12. If volume increases while temperature and moles remain constant, pressure will:
A. Increase
B. Decrease
C. Remain constant
D. Become negative
Answer: B
Rationale: Increasing volume decreases pressure when other variables remain constant.
13. If temperature increases at constant pressure and moles, volume will:
A. Increase
B. Decrease
, C. Remain constant
D. Become negative
Answer: A
Rationale: Volume is directly proportional to absolute temperature at constant pressure.
14. Which law describes the inverse relationship between pressure and volume?
A. Charles's Law
B. Boyle's Law
C. Avogadro's Law
D. Dalton's Law
Answer: B
Rationale: Boyle's Law states that pressure and volume are inversely related at constant
temperature and amount of gas.
15. Which law describes the relationship between volume and absolute temperature?
A. Boyle's Law
B. Charles's Law
C. Dalton's Law
D. Graham's Law
Answer: B
Rationale: Charles's Law states that V/T is constant at constant pressure and amount of gas.
16. Which law relates volume and moles at constant pressure and temperature?
A. Avogadro's Law
B. Boyle's Law
C. Charles's Law
D. Dalton's Law
Answer: A
Rationale: Avogadro's Law states that volume is directly proportional to the number of moles.
17. A gas occupies 2.0 L at 1.0 atm. If pressure doubles at constant temperature, what is the
new volume?
A. 0.5 L
B. 1.0 L
C. 2.0 L
D. 4.0 L
Answer: B
Rationale: Boyle's Law gives P₁V₁ = P₂V₂. Doubling pressure halves volume.
