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Under what conditions of density and pressure does a real gas approximate to an ideal gas?

Correct answer: D. Density=low, pressure=low

  • 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. The conditions under which a real gas approximates an ideal gas include:Low Pressure: At low pressures, the interactions between gas molecules are minimal, and the volume occupied by the gas molecules becomes relatively large compared to the total volume. This makes the real gas behavior approach that of an ideal gas.High Temperature: At high temperatures, the kinetic energy of gas molecules becomes dominant, and the intermolecular forces between them become less significant. This is in line with the assumptions of the kinetic theory of gases, which is the foundation for the ideal gas law.High Volume (Low Density): When the volume occupied by the gas is high (or the density is low), the likelihood of gas molecules coming into close contact and experiencing significant intermolecular forces decreases. In such conditions, the behavior of a real gas is more likely to approximate that of an ideal gas.It's important to note that real gases deviate from ideal behavior under conditions of high pressure and low temperature, where intermolecular forces become more pronounced, and the volume occupied by gas molecules becomes significant compared to the total volume. Under such conditions, deviations from the ideal gas law are more evident, and the use of real gas models or corrections may be necessary.

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About Real and Ideal Gases

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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