Gases MCQs for MDCAT Practice

Chemistry section, Gases chapter. Sample questions from past PMC papers.

1. Question 1
   Under which of the following physical conditions does a real gas approach ideal behavior?
   • A.High temperature and high pressure.
   • B.Low temperature and high pressure.
   • C.High temperature and low pressure.
   • D.Low temperature and low pressure.
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2. Question 2
   The density of a gas X is 6 times the density of a gas Y. If the molecular mass of X is M then what will be the molecular mass of Y?
   • A.M/6
   • B.2M
   • C.6M
   • D.6/M
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3. Question 3
   Which of the following shows marked deviation from ideal behaviour at given temperature and pressure.
   • A.CO2
   • B.He
   • C.H2
   • D.N2
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4. Question 4
   Real gasses behave Ideally at:
   • A.Low temperature and low pressure
   • B.Moderate temperature and low pressure
   • C.High temperature and high pressure
   • D.High temperature and low pressure
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5. Question 5
   In gases & Liquid, Temperature tells about
   • A.Average Rotational Kinetic Energy
   • B.Average Translational Kinetic Energy
   • C.Average Vibrational Kinetic Energy
   • D.All of these
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6. Question 6
   How much pressure in Nm-2 is exerted by one mole of gas enclosed in a vessel of volume 59.4 m3 at 120°C? (Note: R = 8.314 JK-1 mol-1)
   • A.16.79 Nm-2
   • B.21.41Nm-2
   • C.38.21Nm-2
   • D.55.01Nm-2
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7. Question 7
   If the volume of a gas collected at a temperature of 600 °C and pressure of 1.05 × 105 Nm-2 is 60 dm3, what would be the volume of gas at STP (P=1.01 × 105 Nm-2, T = 273 K)?
   • A.100 dm3
   • B.75 dm3
   • C.19.5 dm3
   • D.51 dm3
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8. Question 8
   If a graph is plotted between pressure on x- axis and volume on y- axis for Boyle's law verification, the curve obtained is called
   • A.Pseudotherm
   • B.Isotherm
   • C.Biotherm
   • D.All of these
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