Applying Ideal Gas Law

[kaela_losekoot_2A]

Hi, I was looking over the equilibrium outline and I saw we're supposed to be able to identify reactions where the ideal law can be used as an approximation. What are the conditions that have to be met for the ideal gas law to be applicable, and how can you identify the behavior of a gas as like an ideal gas?

[catluo3K]

To apply the ideal gas law as an approximation, certain conditions must be met:

Low pressure: The pressure of the gas should be relatively low, typically below about 10 atmospheres. At high pressures, gas molecules start to interact with each other, deviating from ideal behavior.

High temperature: The temperature of the gas should be high enough to provide sufficient kinetic energy to the gas molecules, ensuring they move freely and independently. At low temperatures, intermolecular forces become more significant, causing deviations from ideal behavior.

Large volume: The volume occupied by the gas should be large relative to the size of the gas molecules. This condition ensures that the volume of the gas molecules themselves is negligible compared to the overall volume, allowing for ideal behavior.

Gas behavior resembling that of an ideal gas can be identified by several characteristics:

Gas molecules exhibit random motion: Ideal gases consist of particles (atoms or molecules) in constant, random motion. This behavior is evident when observing the diffusion and effusion of the gas.

Gas molecules experience elastic collisions: When gas molecules collide with each other or the walls of the container, they do so without losing kinetic energy. This leads to the conservation of momentum and the absence of energy loss due to collisions.

Gas molecules do not interact with each other: In an ideal gas, molecules do not attract or repel each other, meaning there are no intermolecular forces between them. As a result, the volume of individual molecules is negligible, and they occupy the entire volume of the container uniformly.

Gas obeys Boyle's Law, Charles's Law, and Avogadro's Law: Ideal gases follow these gas laws exactly under the appropriate conditions, which describe the relationships between pressure, volume, temperature, and the number of moles of gas.

While no real gas perfectly adheres to the ideal gas law under all conditions, gases behave more closely to ideal behavior under conditions of low pressure, high temperature, and large volume.

[JeffreyL]

In addition to the other reply, generally unless you are told otherwise you can assume that a gas meets the requirements for an ideal gas if you need to use PV=nRT

[106062642]

When there is little to no intermolecular force between gas molecules, such as at high temperatures, high pressures, and enormous volumes, the ideal gas law is applicable to gases. The ideal gas law equation is followed by the gas under a variety of conditions, indicating ideal gas behavior in terms of pressure, volume, and temperature. Low pressures and high temperatures, where gas molecules can move freely and independently, are more favorable to ideal gas behavior.