## Ideal Gases

$PV=nRT$

Jessica Helfond 2F
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Joined: Fri Sep 28, 2018 12:16 am

### Ideal Gases

How do we know if a gas is ideal? Do we just assume it is in most scenarios?

Maya_Peterson1C
Posts: 62
Joined: Fri Sep 28, 2018 12:28 am

### Re: Ideal Gases

I believe the general assumption is that a gas acts more "ideal" at higher temperatures and at lower pressures. I think most of the problems we will be given deal with ideal gases unless otherwise stated.

Chem_Mod
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### Re: Ideal Gases

In reality, no gas is ideal. An ideal gas is a theoretical gas which we give certain properties which allows us to simplify calculations. We can use these calculations as well as correction factors to make calculations about real gases. The ideal gas law is used to make calculations about ideal gasses. The Van der Waals equation uses correction factors to account for the "un-idealness" of gasses.

Bruce Chen 2H
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Joined: Fri Sep 28, 2018 12:26 am

### Re: Ideal Gases

An ideal gas is a theoretical idea that the gas is in a simple form so that it allows for easier calculation. I think most problems that we are given will only consist of ideal gases.

Eva Zhao 4I
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Joined: Sun Sep 29, 2019 12:16 am

### Re: Ideal Gases

As others have mentioned, an ideal gas is theoretical. Most gases do behave closer to ideal with high temperature and low pressure, however. For most problems, unless stated otherwise, ideal gases should be the ones involved such that we can simplify calculations and use i.e. PV=nRT (ideal gas law).

RobertXu_2J
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Joined: Fri Aug 30, 2019 12:17 am

### Re: Ideal Gases

I do not think a perfectly ideal gas exists, but because the difference is negligible at higher temperatures, we just assume that they are so, to make calculations easier.

605395381
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Joined: Mon Jun 17, 2019 7:24 am

### Re: Ideal Gases

Although gases are never perfectly "ideal". We assume most of the time that gases are ideal because at higher temperature and lower pressure there are not a significant intermolecular forces between the gas molecules. This assumption allows for calculations of other properties of the gases.

Justin Quan 4I
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### Re: Ideal Gases

To add on, generally the rule is that a gas behaves more like an ideal gas at higher temperature and lower pressure. This is because under these conditions, the gas molecules will have little to no intermolecular forces with each other.