Free Gases MCQs with Answers
443 Gases MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Gas behaviour is explained through the kinetic molecular theory and the relationships among pressure, volume and temperature. Work includes STP, Boyle's and Charles's laws, absolute zero, the ideal gas equation, and the distinction between ideal and real gases, especially the effects of intermolecular forces and molecular volume.
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443 questions · page 8 of 23
- A. Boyle's law
- B. Charles' law
- C. Avogadro's law
- D. Pascal's law
Explanation: Avogadro's Law has pressure and temperature as constant. This is when Volume is directly proportional to the number of moles.
Correct answer: Avogadro's law- A. 8.314Jmol-1K-1
- B. 8.314 dm3 atm mol-lK-1
- C. 0.0821dm3 atm mol-1 K-1
- D. 0.0821Jmol-1K-1
Explanation: The universal gas constant value is 8.314 Jmol-1K-1.
Correct answer: 8.314Jmol-1K-1143. If pressure and volume of a gas are variable while temperature remains constant, this belongs to
- A. Charles's law
- B. Boyle's law
- C. Avogadro's law
- D. Pascal's law
Explanation: Boyle's law is a gas law, stating that the pressure and volume of a gas have an inverse relationship.
Correct answer: Boyle's law144. For a non-zero value of the force of attraction between gas molecules, the gas equation will be:
- A. PV = nRT - n²A / V
- B. PV = nRT + nbP
- C. P = nRT / V - b
- D. PV = nRT
Explanation: The van der Waals equation modifies the ideal gas law for real gases. The term 'a' corrects for the intermolecular forces of attraction…
Correct answer: PV = nRT - n²A / V- A. Less than 22.4L
- B. Greater than 22.4L
- C. Equal to 22.4L
- D. None of these
Explanation: The compressibility factor Z=PV/RT. If Z > 1, it means the real volume is greater than the ideal volume.
Correct answer: Greater than 22.4L- A. √2v
- B. 2v
- C. v
- D. 4v
Explanation: When the temperature of nitrogen gas (N₂) is doubled, the root mean square (rms) speed for the N₂ molecules increases by a factor of √2…
Correct answer: 2v- A. Increases on increasing temperature
- B. Decreases on increasing temperature
- C. Unchanged on changing temperature
- D. Increases somewhere and decreases
Explanation: Mean free path is the average distance a molecule travels between collisions.
Correct answer: Unchanged on changing temperature- A. RT
- B. a/Vm
- C. b
- D. Cannot be determined
Explanation: For a real gas obeying van der Waal's equation, a graph is plotted between PVm (y-axis) and P (x-axis), where Vm is molar volume.
Correct answer: RT- A. O2
- B. SO2
- C. NO
- D. C4H10
Explanation: To determine the identity of gas X, we compare the given conditions for CO2 and gas X under the same pressure and temperature.
Correct answer: SO2- A. 6
- B. 1/6
- C. 2/3
- D. 3/2
Explanation: This is the following solution:To determine the ratio of the pressures of gases A and B, let's use the ideal gas law equation: PV NRTThis…
Correct answer: 6- A. The constant 'a' is negligible and not 'b'
- B. The constant 'b' is negligible and not 'a'
- C. Both constants 'a' & 'b' are negligible
- D. Both the constants 'a' & 'b' are not negligible
Explanation: At high pressures, molecules are close together, so the molecular volume (related to 'b') is no longer negligible.
Correct answer: The constant 'a' is negligible and not 'b'- A. 6.5
- B. 2.23
- C. 23.2
- D. 85
Explanation: Given:Pressure (P) = 11 atmVolume (V) = 4 LNumber of moles (n) = 2 molesTemperature (T) = 300 KIdeal gas constant (R) = 0.0821 L atm /…
Correct answer: 6.5- A. 1 L
- B. 0.1 L
- C. 1.05 L
- D. 1.50 L
Explanation: Using Charles's Law (V₁/T₁ = V₂/T₂), with temperatures in Kelvin. T₁ = 0°C = 273 K, and T₂ = 300°C = 573 K.
Correct answer: 1.05 L- A. The average kinetic energy of the gas molecules decreases
- B. Gas molecules collide more frequently with the container walls
- C. Gas molecules collide less frequently with the container walls
- D. Gas molecules collide less energetically with the container walls
Explanation: According to the Kinetic Molecular Theory, as temperature increases, the average kinetic energy of gas molecules also increases.
Correct answer: Gas molecules collide more frequently with the container walls- A. 100%
- B. 50%
- C. 40%
- D. 200%
Explanation: Ideal Gas Law:The ideal gas law states: PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant…
Correct answer: 100%- A. 34 mL
- B. 10 mL
- C. 30 mL
- D. 60 mL
Explanation: PV = nRT, V = (0.001*0.0821*300)/0.175= 140.6ml Total bulb = 150ml → 140.6-150 ≈ 10ml
Correct answer: 10 mL- A. 4
- B. 2
- C. 0.449
- D. 1
Explanation: Step 1: Write the ratio expressionvrms (H2 ,50K) /vrms (O2 ,800K) = √TH2.Mo2/MH2.TO2 Step 2: Substitute values√50 X 0.032 / 0.002 X 800…
Correct answer: 1- A. P(Vm −b)=RT
- B. (P+a/V2m)Vm =RT
- C. PVm=RTP
- D. (P−b)(Vm −a/V2m)=RT
Explanation: The Van der Waals equation simplifies by dropping the pressure correction term but keeping the volume correction term, which…
Correct answer: P(Vm −b)=RT- A. T(H2) = T(N2)
- B. T(H2) > T(N2)
- C. T(H2) < T(N2)
- D. T(H2) = √7 T(N2)
Explanation: The rms velocity is v = √(3RT/M). Given v(H₂) = √7 v(N₂), we can set up the equation √(3RT(H₂)/M(H₂)) = √7 √(3RT(N₂)/M(N₂)).
Correct answer: T(H2) < T(N2)- A. Vm > 22.4 litres
- B. Vm < 22.4 litres
- C. Vm = 22.4 litres
- D. Vm = 44.8 litres
Explanation: The compressibility factor Z = V / V . If Z is less than 1, it means the real molar volume (Vm) is less than the ideal molar volume.
Correct answer: Vm < 22.4 litres