What are the limitations of the Ideal Gas Law?

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SUMMARY

The Ideal Gas Law, represented by the equation PV=nRT, has limitations primarily due to the assumptions of no intermolecular forces and negligible molecular volume. These assumptions hold true at low pressures where gas molecules are far apart, but fail at high pressures or low temperatures where real gases deviate from ideal behavior. In such cases, the Van der Waals equation should be utilized to account for these deviations and provide more accurate predictions of gas behavior.

PREREQUISITES
  • Understanding of the Ideal Gas Law (PV=nRT)
  • Familiarity with Charles's Law and Boyle's Law
  • Knowledge of real gas behavior and conditions affecting it
  • Basic grasp of the Van der Waals equation
NEXT STEPS
  • Study the Van der Waals equation in detail
  • Explore the conditions under which real gases deviate from ideal behavior
  • Learn about other equations of state for gases, such as the Redlich-Kwong equation
  • Investigate the impact of temperature and pressure on gas behavior
USEFUL FOR

Chemistry students, physicists, and engineers who require a deeper understanding of gas behavior and the limitations of the Ideal Gas Law.

optrix
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I've been looking at Charles law, Boyles law, the Pressure law, and the Ideal gas law, PV=nRT. I want to know, what limitations are there to the gas law? Basically, why aren't real gasses ideal, when isn't it possible to use the ideal gas law, and in such a case, what else do you have to use instead? Thanks a lot.
 
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For ideal gases, we are assuming that there are no intermolecular forces and that the molecules themselves take up no volume. This is quite true at low pressures, because the spacing between the molecules is so large that they rarely collide. Also low pressure usually means that there is little of them or that the volume of the container is very large, so the space taken up by the actual molecules is negligible.

If you are dealing with cases where this is not true, you use the Van der Waals equation:
http://en.wikipedia.org/wiki/Van_der_Waals_equation
 
Thanks for the help!
 

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