Free Real and Ideal Gases MCQs with Answers

97 Real and Ideal 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.

An ideal gas is modelled as particles with negligible volume and no intermolecular attraction, obeying Boyle's, Charles's and Avogadro's laws through PV = nRT. Real gases deviate from this behaviour, especially at high pressure and low temperature, because particle volume and attractive forces matter; the van der Waals equation explains these corrections.

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97 questions · page 3 of 5

  • A. n2a/v correct for the intermolecular forces.
  • B. nb correct for the volume occupied by gas molecules.
  • C. at high densities the equation reduces to the ideal gas law
  • D. all of the above statements are correct.

Explanation: In the van der Waals equation, the pressure correction n2a/v2 accounts for intermolecular attraction and the volume correction nb accounts…

Correct answer: at high densities the equation reduces to the ideal gas law
  • A. C*O_{2}
  • B. N_{2}
  • C. H_{2}
  • D. SO2

Explanation: Presence of electrons is large in sulphur dioxide and hence greater van der waals interactions .

Correct answer: SO2
  • A. High Pressure = High Density =High temp
  • B. Low Pressure = Low Density = High temp
  • C. High Pressure = High Density = Low temp
  • D. Low Pressure = Low Density = Low temp

Explanation: A real gas behaves most like an ideal gas at high temperatures and low pressures.

Correct answer: Low Pressure = Low Density = High temp
  • A. Density=high, pressure=high
  • B. Density=low, pressure=high
  • C. Density=high, pressure=low
  • D. Density=low, pressure=low

Explanation: A real gas approaches the behavior of an ideal gas under certain conditions.

Correct answer: Density=low, pressure=low
  • A. At low pressure and high temperature
  • B. At high pressure and high temperature
  • C. At low pressure and low temperature
  • D. At high pressure and low temperature

Explanation: At high pressure and low temperature, a gas deviates the most from its ideal behavior.

Correct answer: At high pressure and low temperature
  • A. Low temperature and low pressure
  • B. Moderate temperature and low pressure
  • C. High temperature and low pressure
  • D. High temperature and high pressure

Explanation: Generally gas behaves more like an ideal gas at higher temperature and low pressure, as P.E due to intermolecular forces become less…

Correct answer: High temperature and low pressure
  • A. 1 atm
  • B. 4 atm
  • C. 6 atm
  • D. 8 atm

Explanation: The actual volume of the molecules of a gas is usually very small as compared to the volume of the vessel and hence it can be neglected.

Correct answer: 1 atm
  • A. SO2
  • B. NH3
  • C. H2
  • D. H2S

Explanation: In order to understand the answer to this question, we first need to address the definition of an ideal gas:Hydrogen is the closest to…

Correct answer: H2
  • A. Low temperature, high pressure
  • B. High temperature, high pressure
  • C. Low temperature, low pressure
  • D. High temperature, low pressure

Explanation: At high temperatures and low pressure, molecules of a gas are far apart, with minimal forces of attraction between them.

Correct answer: High temperature, low pressure
  • A. Intermolecular forces
  • B. Decrease in volume occupied by gas
  • C. All of these
  • D. Decrease in compressibility of gas

Explanation: Ideal gases are those that have no intermolecular forces, their molecular volume is negligible as compared to the volume of the entire gas…

Correct answer: All of these
  • A. Pressure = hign density = high
  • B. Pressure = low density = high
  • C. Pressure = high density = low
  • D. Pressure= low density= low

Explanation: This option represents conditions where both the pressure and density of the gas are low.

Correct answer: Pressure= low density= low
  • A. mol dm-3
  • B. dm3
  • C. m3 mol-1
  • D. m3 mol

Explanation: Option A: This unit represents the concentration of a substance in moles per cubic decimeter.

Correct answer: m3 mol-1
  • A. Ammonia
  • B. Hydrogen
  • C. Helium
  • D. Radon

Explanation: OPTION A: Ammonia deviates from ideal behavior due to its molecular structure and hydrogen bonding, which influences its behavior.OPTION…

Correct answer: Helium
  • A. Oxygen and nitrogen
  • B. Carbon dioxide and oxygen
  • C. Helium and oxygen
  • D. Helium and hydrogen

Explanation: Helium and oxygen are taken as a mix to adjust the partial pressure of oxygen according to the requirement.

Correct answer: Helium and oxygen
  • A. Small
  • B. Large
  • C. Equal
  • D. None of these options are correct

Explanation: If a and b are small, a/V2 and b can be neglected as compared to P and V and the equation reduces to PV=RT.

Correct answer: Small
  • A. 0.266
  • B. 0.366
  • C. 0.318
  • D. 0.562

Explanation: Van Der Waals forces is a general term used to define the attraction of intermolecular forces between molecules.

Correct answer: 0.266
  • A. Methane
  • B. Carbon dioxide
  • C. Hydrogen
  • D. Helium

Explanation: Helium is non-polar, so it is not easy to operate attractive forces. So they can't be liquified by Linda's method.

Correct answer: Helium
  • A. Joule-Thomson effect
  • B. Hess effect
  • C. Graham's effect
  • D. none of these

Explanation: Linde's method is based on Joule 's-Thomson effect. Linde's process is known as the Adiabatic expansion of compressed gas.

Correct answer: Joule-Thomson effect
  • A. 31.14
  • B. 13.24
  • C. 132.44
  • D. 1.11

Explanation: Option C is correct since Ammonia (NH3)'s critical temperature is 132.4 °C (405.5 K)

Correct answer: 132.44
  • A. Raise
  • B. Higher
  • C. Equalize
  • D. Lower

Explanation: The Joule-Thomson effect is used to lower the temperature of a gas to liquefy it.

Correct answer: Lower