Ideal gas law - Revision history

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	[[Category:Done ~~2019~~-09-05]]		[[Category:Done 2021-01-31]]
	<onlyinclude>The '''ideal gas law''' provides the basis for understanding [[heat engine]]s, how airbags work, and even [[tire pressure]].</onlyinclude> The principle equation for the ideal gas law is:<ref>"The Ideal Gas Law", Chemistry LibreTexts, 2018. [Online]. Available: https://chem.libretexts.org/Textbook_Maps/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Physical_Properties_of_Matter/States_of_Matter/Properties_of_Gases/Gas_Laws/The_Ideal_Gas_Law. [Accessed: 25- Jul- 2018].</ref>		<onlyinclude>The '''ideal gas law''' provides the basis for understanding [[heat engine]]s, how airbags work, and even [[tire pressure]].</onlyinclude> The principle equation for the ideal gas law is:<ref>"The Ideal Gas Law", Chemistry LibreTexts, 2018. [Online]. Available: https://chem.libretexts.org/Textbook_Maps/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Physical_Properties_of_Matter/States_of_Matter/Properties_of_Gases/Gas_Laws/The_Ideal_Gas_Law. [Accessed: 25- Jul- 2018].</ref>

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	The value of R depends on the units used. It can also be written as <math>pV = Nk_B T</math> where ''N'' is the number of [[molecule]]s and <math>k_B</math> is [[Boltzmann's constant]], with the rest of the variables being the same.		The value of R depends on the units used. It can also be written as <math>pV = Nk_B T</math> where ''N'' is the number of [[molecule]]s and <math>k_B</math> is [[Boltzmann's constant]], with the rest of the variables being the same.

	The ideal gas law allows ~~for~~ us to determine what will happen to a contained system with an '''ideal gas''' inside, based on these different variables. An ideal gas is one that ''never condenses'' regardless of the various changes its state variables (pressure, volume, temperature) undergo. For example, if the volume of the system is increased, and all other variables are left alone, the pressure will automatically decrease to compensate for the increase in volume. Conversely, if heat is added to a system, both its volume and pressure will increase to compensate. This latter relationship is the basis for [[heat engine]]s.
			The ideal gas law allows us to determine what will happen to a contained system with an '''ideal gas''' inside, based on these different variables. An ideal gas is one that ''never condenses'' regardless of the various changes its state variables (pressure, volume, temperature) undergo. For example, if the volume of the system is increased, and all other variables are left alone, the pressure will automatically decrease to compensate for the increase in volume. Conversely, if heat is added to a system, both its volume and pressure will increase to compensate. This latter relationship is the basis for [[heat engine]]s.
	For a deeper treatment of the ideal gas law please see [http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/idgcon.html#c1 hyperphysics], for an extensive treatment please see the [http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Phases_of_Matter/Gases/The_Ideal_Gas_Law UC Davis's chem wiki].		For a deeper treatment of the ideal gas law please see [http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/idgcon.html#c1 hyperphysics], for an extensive treatment please see the [http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Phases_of_Matter/Gases/The_Ideal_Gas_Law UC Davis's chem wiki].

	==How an ~~airbag works~~==		For more information on the assumptions behind the ideal gas law, visit the page on [[ideal gas approximation]]s.

			==How an Airbag Works==
	[[File:airbag_car.jpg\|400px\|right\|thumb\|Airbags inflate quickly in the case of an accident and reduce injuries. The ideal gas law says that rapidly changing the number of particles (<math>n</math> or <math>N</math>) make <math>p</math> and <math>V</math> increase rapidly.<ref>Hyundai's Safety: Airbags https://www.flickr.com/photos/alanchan/2267907489 [Accessed: 13- Aug- 2018].</ref>]]		[[File:airbag_car.jpg\|400px\|right\|thumb\|Airbags inflate quickly in the case of an accident and reduce injuries. The ideal gas law says that rapidly changing the number of particles (<math>n</math> or <math>N</math>) make <math>p</math> and <math>V</math> increase rapidly.<ref>Hyundai's Safety: Airbags https://www.flickr.com/photos/alanchan/2267907489 [Accessed: 13- Aug- 2018].</ref>]]
	Oftentimes, physics and chemistry's applications seem quite distant. Here's an example of how these sciences can save a life during a car crash.		Oftentimes, physics and chemistry's applications seem quite distant. Here's an example of how these sciences can save a life during a car crash.

	Vehicle airbags work using the ideal gas law. By reacting Sodium Azide, <chem>NaN_3</chem>, with excess heat, a large amount of Nitrogen gas (<chem>N_2</chem>) is created. The balanced chemical formula for this is <math>2NaN_3 + heat \Rightarrow 2Na_ + 3N_2</math>. How does this pertain to the ideal gas law? If you recall, in the ideal gas equation, <math>n</math> is equal to the number of [[mole]]s (a unit of amount) of gas in the system. Before the reaction, the sodium azide is a solid, so there is no gas in the system. By reacting the sodium azide to create nitrogen gas, several moles of gas are added to the system. The ideal gas law says the two sides of the <math>pV = nRT</math> equation have to balance; adding moles of nitrogen gas forces the volume of the system to increase dramatically. This inflates the airbag in between 20-40 milliseconds, giving it time to begin deflating before a driver's head hits it. This disperses the force, dramatically improving chances of avoiding serious injury.<ref>"How do ~~air bags~~ work?", Scientific American, 2018. [Online]. Available: https://www.scientificamerican.com/article/how-do-air-bags-work/. [Accessed: 25- Jul- 2018].</ref>		Vehicle airbags work using the ideal gas law. By reacting Sodium Azide, <chem>NaN_3</chem>, with excess heat, a large amount of Nitrogen gas (<chem>N_2</chem>) is created. The balanced chemical formula for this is <math>2NaN_3 + heat \Rightarrow 2Na_ + 3N_2</math>. How does this pertain to the ideal gas law? If you recall, in the ideal gas equation, <math>n</math> is equal to the number of [[mole]]s (a unit of amount) of gas in the system. Before the reaction, the sodium azide is a solid, so there is no gas in the system. By reacting the sodium azide to create nitrogen gas, several moles of gas are added to the system. The ideal gas law says the two sides of the <math>pV = nRT</math> equation have to balance; adding moles of nitrogen gas forces the volume of the system to increase dramatically. This inflates the airbag in between 20-40 milliseconds, giving it time to begin deflating before a driver's head hits it. This disperses the force, dramatically improving the chances of avoiding serious injury.<ref>"How do airbags work?", Scientific American, 2018. [Online]. Available: https://www.scientificamerican.com/article/how-do-air-bags-work/. [Accessed: 25- Jul- 2018].</ref>

	==PhET: States of Matter==		==PhET: States of Matter==
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	==For Further Reading==		==For Further Reading==
			*[[Ideal gas approximation]]
	*[[Pressure volume diagram]]		*[[Pressure volume diagram]]
	*[[Ideal gas constant]]		*[[Ideal gas constant]]

Jmdonev: 1 revision imported

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energy>Jmdonev at 19:49, 4 September 2019

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	<onlyinclude>The '''ideal gas law''' provides the basis for understanding [[heat engine]]s, how airbags work, and even [[tire pressure]].</onlyinclude> The principle equation for the ideal gas law is:<ref>"The Ideal Gas Law", Chemistry LibreTexts, 2018. [Online]. Available: https://chem.libretexts.org/Textbook_Maps/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Physical_Properties_of_Matter/States_of_Matter/Properties_of_Gases/Gas_Laws/The_Ideal_Gas_Law. [Accessed: 25- Jul- 2018].</ref>		<onlyinclude>The '''ideal gas law''' provides the basis for understanding [[heat engine]]s, how airbags work, and even [[tire pressure]].</onlyinclude> The principle equation for the ideal gas law is:<ref>"The Ideal Gas Law", Chemistry LibreTexts, 2018. [Online]. Available: https://chem.libretexts.org/Textbook_Maps/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Physical_Properties_of_Matter/States_of_Matter/Properties_of_Gases/Gas_Laws/The_Ideal_Gas_Law. [Accessed: 25- Jul- 2018].</ref>

	<center><math>pV = nRT</math></center> where:		<center><math>pV = nRT</math></center> where:
	*<math>p</math> is pressure		*<math>p</math> is [[pressure]]
	*<math>V</math> is volume		*<math>V</math> is [[volume]]
	*<math>n</math> is the number of [[mole]]s of gas		*<math>n</math> is the number of [[mole]]s of gas
	*<math>T</math> is temperature (measured in [[kelvin]])		*<math>T</math> is [[temperature]] (measured in [[kelvin]])
	*<math>R</math> is the [[ideal gas constant]]		*<math>R</math> is the [[ideal gas constant]]

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	Vehicle airbags work using the ideal gas law. By reacting Sodium Azide, <chem>NaN_3</chem>, with excess heat, a large amount of Nitrogen gas (<chem>N_2</chem>) is created. The balanced chemical formula for this is <math>2NaN_3 + heat \Rightarrow 2Na_ + 3N_2</math>. How does this pertain to the ideal gas law? If you recall, in the ideal gas equation, <math>n</math> is equal to the number of [[mole]]s (a unit of amount) of gas in the system. Before the reaction, the sodium azide is a solid, so there is no gas in the system. By reacting the sodium azide to create nitrogen gas, several moles of gas are added to the system. The ideal gas law says the two sides of the <math>pV = nRT</math> equation have to balance; adding moles of nitrogen gas forces the volume of the system to increase dramatically. This inflates the airbag in between 20-40 milliseconds, giving it time to begin deflating before a driver's head hits it. This disperses the force, dramatically improving chances of avoiding serious injury.<ref>"How do air bags work?", Scientific American, 2018. [Online]. Available: https://www.scientificamerican.com/article/how-do-air-bags-work/. [Accessed: 25- Jul- 2018].</ref>		Vehicle airbags work using the ideal gas law. By reacting Sodium Azide, <chem>NaN_3</chem>, with excess heat, a large amount of Nitrogen gas (<chem>N_2</chem>) is created. The balanced chemical formula for this is <math>2NaN_3 + heat \Rightarrow 2Na_ + 3N_2</math>. How does this pertain to the ideal gas law? If you recall, in the ideal gas equation, <math>n</math> is equal to the number of [[mole]]s (a unit of amount) of gas in the system. Before the reaction, the sodium azide is a solid, so there is no gas in the system. By reacting the sodium azide to create nitrogen gas, several moles of gas are added to the system. The ideal gas law says the two sides of the <math>pV = nRT</math> equation have to balance; adding moles of nitrogen gas forces the volume of the system to increase dramatically. This inflates the airbag in between 20-40 milliseconds, giving it time to begin deflating before a driver's head hits it. This disperses the force, dramatically improving chances of avoiding serious injury.<ref>"How do air bags work?", Scientific American, 2018. [Online]. Available: https://www.scientificamerican.com/article/how-do-air-bags-work/. [Accessed: 25- Jul- 2018].</ref>

			==PhET: States of Matter==
			The [http://phet.colorado.edu/ University of Colorado] has graciously allowed us to use the following Phet simulation. Explore the simulation to see how particles moving around in a gas lead to various gas properties:
			<html>
			<iframe src="https://phet.colorado.edu/sims/html/gas-properties/latest/gas-properties_en.html" width="800" height="600" scrolling="no" allowfullscreen></iframe>
			</html>


	==For Further Reading==		==For Further Reading==

Jmdonev: 1 revision imported

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energy>Jmdonev at 22:15, 13 August 2018

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	[[Category:Done ~~2017~~-07-~~01]]~~		[[Category:Done 2018-08-03]]
	~~[[Category: Needs citations~~]]		<onlyinclude>The '''ideal gas law''' provides the basis for understanding [[heat engine]]s, how airbags work, and even [[tire pressure]].</onlyinclude> The principle equation for the ideal gas law is:<ref>"The Ideal Gas Law", Chemistry LibreTexts, 2018. [Online]. Available: https://chem.libretexts.org/Textbook_Maps/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Physical_Properties_of_Matter/States_of_Matter/Properties_of_Gases/Gas_Laws/The_Ideal_Gas_Law. [Accessed: 25- Jul- 2018].</ref>
	<onlyinclude>The '''ideal gas law''' ~~is a fundamental law to physics, and it~~ provides the basis for heat ~~engines~~, ~~as well as explains~~ how airbags work, and ~~why an empty water bottle can sometimes pop when you take it on an airplane~~.</onlyinclude> The principle equation for the ideal gas law is <~~math~~>~~pV = nRT</math>. In this equation <math>p</math> is pressure~~, ~~<math>V</math> is volume~~, ~~<math>n</math> is the number of~~ [~~[mole~~]~~]s of gas,<math>T<~~/~~math> is temperature, and <math>R<~~/~~math> is the [[ideal gas constant]]~~. ~~The value of R depends on the units used~~. ~~It can also be written as <math>pV = Nk_B T<~~/~~math> where ''N'' is the number of~~ [~~[molecule~~]~~]s and <math>k_B~~</~~math~~> ~~is [[Boltzmann's constant]], with the rest of the variables being the same.~~

	~~The ideal gas law allows for us to determine what will happen to a contained system with gas inside, based on these different variables. For example, if the volume of the system~~ is ~~increased, and all other variables are left alone, the~~ pressure ~~will automatically decrease to compensate for the increase in volume. Conversely, if heat~~ is ~~added to a system, both its~~ volume ~~and pressure will increase to compensate. This latter relationship~~ is the ~~basis for~~ [[~~heat engine~~]]s.		<center><math>pV = nRT</math></center> where:
			*<math>p</math> is pressure
			*<math>V</math> is volume
			*<math>n</math> is the number of [[mole]]s of gas
			*<math>T</math> is temperature (measured in [[kelvin]])
			*<math>R</math> is the [[ideal gas constant]]

			The value of R depends on the units used. It can also be written as <math>pV = Nk_B T</math> where ''N'' is the number of [[molecule]]s and <math>k_B</math> is [[Boltzmann's constant]], with the rest of the variables being the same.

			The ideal gas law allows for us to determine what will happen to a contained system with an '''ideal gas''' inside, based on these different variables. An ideal gas is one that ''never condenses'' regardless of the various changes its state variables (pressure, volume, temperature) undergo. For example, if the volume of the system is increased, and all other variables are left alone, the pressure will automatically decrease to compensate for the increase in volume. Conversely, if heat is added to a system, both its volume and pressure will increase to compensate. This latter relationship is the basis for [[heat engine]]s.
	For a deeper treatment of the ideal gas law please see [http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/idgcon.html#c1 hyperphysics], for an extensive treatment please see the [http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Phases_of_Matter/Gases/The_Ideal_Gas_Law UC Davis's chem wiki].		For a deeper treatment of the ideal gas law please see [http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/idgcon.html#c1 hyperphysics], for an extensive treatment please see the [http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Phases_of_Matter/Gases/The_Ideal_Gas_Law UC Davis's chem wiki].

	==How an airbag works==		==How an airbag works==
			[[File:airbag_car.jpg\|400px\|right\|thumb\|Airbags inflate quickly in the case of an accident and reduce injuries. The ideal gas law says that rapidly changing the number of particles (<math>n</math> or <math>N</math>) make <math>p</math> and <math>V</math> increase rapidly.<ref>Hyundai's Safety: Airbags https://www.flickr.com/photos/alanchan/2267907489 [Accessed: 13- Aug- 2018].</ref>]]
	Oftentimes, physics and chemistry's applications seem quite distant. Here's an example of how these sciences can save a life during a car crash.		Oftentimes, physics and chemistry's applications seem quite distant. Here's an example of how these sciences can save a life during a car crash.

	Vehicle airbags work using the ideal gas law. By reacting Sodium Azide, <chem>NaN_3</chem>, with excess heat, a large amount of Nitrogen gas (<chem>N_2</chem>) is created. The balanced chemical formula for this is <math>2NaN_3 \Rightarrow 2Na_ + 3N_2</math>. How does this pertain to the ideal gas law? If you recall, in the ideal gas equation, <math>n</math> is equal to the number of ~~moles~~ (a unit of amount) of gas in the system. Before the reaction, the sodium azide is a solid, so there is no gas in the system. By reacting the sodium azide to create nitrogen gas, ~~we add~~ several moles of gas to the system. ~~As we remember with the~~ ideal gas law, the two sides of the <math>pV = nRT</math> equation have to balance~~, so by~~ adding ~~a bunch of~~ moles of nitrogen gas~~, we force~~ the volume of the system to increase dramatically. This inflates the airbag in between 20-40 milliseconds, giving it time to begin deflating before ~~your~~ head hits it. This disperses the force, dramatically improving chances of avoiding serious injury.<ref>~~http~~://www.scientificamerican.com/article/how-do-air-bags-work/</ref>		Vehicle airbags work using the ideal gas law. By reacting Sodium Azide, <chem>NaN_3</chem>, with excess heat, a large amount of Nitrogen gas (<chem>N_2</chem>) is created. The balanced chemical formula for this is <math>2NaN_3 + heat \Rightarrow 2Na_ + 3N_2</math>. How does this pertain to the ideal gas law? If you recall, in the ideal gas equation, <math>n</math> is equal to the number of [[mole]]s (a unit of amount) of gas in the system. Before the reaction, the sodium azide is a solid, so there is no gas in the system. By reacting the sodium azide to create nitrogen gas, several moles of gas are added to the system. The ideal gas law says the two sides of the <math>pV = nRT</math> equation have to balance; adding moles of nitrogen gas forces the volume of the system to increase dramatically. This inflates the airbag in between 20-40 milliseconds, giving it time to begin deflating before a driver's head hits it. This disperses the force, dramatically improving chances of avoiding serious injury.<ref>"How do air bags work?", Scientific American, 2018. [Online]. Available: https://www.scientificamerican.com/article/how-do-air-bags-work/. [Accessed: 25- Jul- 2018].</ref>

			==For Further Reading==
			*[[Pressure volume diagram]]
			*[[Ideal gas constant]]
			*[[Mole]]
			*[[Molecule]] and [[Avogadro's number]]
			*Or explore a [[Special:Random\|random page]]

	==References==		==References==
	{{reflist}}		{{reflist}}
	[[Category:Uploaded]]		[[Category:Uploaded]]

Jmdonev: 1 revision imported

2017-08-29T01:47:38Z

1 revision imported

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Jmdonev at 07:04, 27 August 2017

2017-08-27T07:04:53Z

← Older revision		Revision as of 07:04, 27 August 2017
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	[[Category:Done ~~2015~~-03-06]] [[Category: Needs citations]]		[[Category:Done 2017-07-01]]
	<onlyinclude>The '''ideal gas law''' is a fundamental law to physics, and it provides the basis for heat engines, as well as explains how airbags work, and why an empty water bottle can sometimes pop when you take it on an airplane.</onlyinclude> The principle equation for the ideal gas law is <m>pV = nRT</m>. In this equation <m>p</m> is pressure, <m>V</m> is volume, <m>n</m> is the number of [[mole]]s of gas,<m>T</m> is temperature, and <m>R</m> is the [[ideal gas constant]]. The value of R depends on the units used. It can also be written as <m>pV = Nk_B T</m> where ''N'' is the number of [[molecule]]s and <m>k_B</m> is [[Boltzmann's constant]], with the rest of the variables being the same.		[[Category: Needs citations]]
			<onlyinclude>The '''ideal gas law''' is a fundamental law to physics, and it provides the basis for heat engines, as well as explains how airbags work, and why an empty water bottle can sometimes pop when you take it on an airplane.</onlyinclude> The principle equation for the ideal gas law is <math>pV = nRT</math>. In this equation <math>p</math> is pressure, <math>V</math> is volume, <math>n</math> is the number of [[mole]]s of gas,<math>T</math> is temperature, and <math>R</math> is the [[ideal gas constant]]. The value of R depends on the units used. It can also be written as <math>pV = Nk_B T</math> where ''N'' is the number of [[molecule]]s and <math>k_B</math> is [[Boltzmann's constant]], with the rest of the variables being the same.

	The ideal gas law allows for us to determine what will happen to a contained system with gas inside, based on these different variables. For example, if the volume of the system is increased, and all other variables are left alone, the pressure will automatically decrease to compensate for the increase in volume. Conversely, if heat is added to a system, both its volume and pressure will increase to compensate. This latter relationship is the basis for [[heat engine]]s.		The ideal gas law allows for us to determine what will happen to a contained system with gas inside, based on these different variables. For example, if the volume of the system is increased, and all other variables are left alone, the pressure will automatically decrease to compensate for the increase in volume. Conversely, if heat is added to a system, both its volume and pressure will increase to compensate. This latter relationship is the basis for [[heat engine]]s.
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	Oftentimes, physics and chemistry's applications seem quite distant. Here's an example of how these sciences can save a life during a car crash.		Oftentimes, physics and chemistry's applications seem quite distant. Here's an example of how these sciences can save a life during a car crash.

	Vehicle airbags work using the ideal gas law. By reacting Sodium Azide ~~(NaN~~<~~sub~~>3</~~sub~~>) with excess heat, a large amount of Nitrogen gas (N<~~sub~~>2</~~sub~~>) is created. The balanced chemical formula for this is ~~2NaN<sub>3 (solid)</sub> --> 2Na <sub>(solid)~~<~~/sub~~> + ~~3N<sub>2 (gas)~~</~~sub~~>. How does this pertain to the ideal gas law? If you recall, in the ideal gas equation, <m>n</m> is equal to the number of moles (a unit of amount) of gas in the system. Before the reaction, the sodium azide is a solid, so there is no gas in the system. By reacting the sodium azide to create nitrogen gas, we add several moles of gas to the system. As we remember with the ideal gas law, the two sides of the <m>pV = nRT</m> equation have to balance, so by adding a bunch of moles of nitrogen gas, we force the volume of the system to increase dramatically. This inflates the airbag in between 20-40 milliseconds, giving it time to begin deflating before your head hits it. This disperses the force, dramatically improving chances of avoiding serious injury.<ref>http://www.scientificamerican.com/article/how-do-air-bags-work/</ref>		Vehicle airbags work using the ideal gas law. By reacting Sodium Azide, <chem>NaN_3</chem>, with excess heat, a large amount of Nitrogen gas (<chem>N_2</chem>) is created. The balanced chemical formula for this is <math>2NaN_3 \Rightarrow 2Na_ + 3N_2</math>. How does this pertain to the ideal gas law? If you recall, in the ideal gas equation, <math>n</math> is equal to the number of moles (a unit of amount) of gas in the system. Before the reaction, the sodium azide is a solid, so there is no gas in the system. By reacting the sodium azide to create nitrogen gas, we add several moles of gas to the system. As we remember with the ideal gas law, the two sides of the <math>pV = nRT</math> equation have to balance, so by adding a bunch of moles of nitrogen gas, we force the volume of the system to increase dramatically. This inflates the airbag in between 20-40 milliseconds, giving it time to begin deflating before your head hits it. This disperses the force, dramatically improving chances of avoiding serious injury.<ref>http://www.scientificamerican.com/article/how-do-air-bags-work/</ref>

	==References==		==References==
	{{reflist}}		{{reflist}}
	[[Category:Uploaded]]		[[Category:Uploaded]]

J.williams: 1 revision imported

2015-08-26T21:31:11Z

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J.williams at 16:54, 12 August 2015

2015-08-12T16:54:46Z

New page

[[Category:Done 2015-03-06]] [[Category: Needs citations]]
<onlyinclude>The '''ideal gas law''' is a fundamental law to physics, and it provides the basis for heat engines, as well as explains how airbags work, and why an empty water bottle can sometimes pop when you take it on an airplane.</onlyinclude> The principle equation for the ideal gas law is <m>pV = nRT</m>. In this equation <m>p</m> is pressure, <m>V</m> is volume, <m>n</m> is the number of [[mole]]s of gas,<m>T</m> is temperature, and <m>R</m> is the [[ideal gas constant]]. The value of R depends on the units used. It can also be written as <m>pV = Nk_B T</m> where ''N'' is the number of [[molecule]]s and <m>k_B</m> is [[Boltzmann's constant]], with the rest of the variables being the same.

The ideal gas law allows for us to determine what will happen to a contained system with gas inside, based on these different variables. For example, if the volume of the system is increased, and all other variables are left alone, the pressure will automatically decrease to compensate for the increase in volume. Conversely, if heat is added to a system, both its volume and pressure will increase to compensate. This latter relationship is the basis for [[heat engine]]s.

For a deeper treatment of the ideal gas law please see [http://hyperphysics.phy-astr.gsu.edu/hbase/kinetic/idgcon.html#c1 hyperphysics], for an extensive treatment please see the [http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Phases_of_Matter/Gases/The_Ideal_Gas_Law UC Davis's chem wiki].

==How an airbag works==
Oftentimes, physics and chemistry's applications seem quite distant. Here's an example of how these sciences can save a life during a car crash.

Vehicle airbags work using the ideal gas law. By reacting Sodium Azide (NaN3) with excess heat, a large amount of Nitrogen gas (N2) is created. The balanced chemical formula for this is 2NaN3 (solid) --> 2Na (solid) + 3N2 (gas). How does this pertain to the ideal gas law? If you recall, in the ideal gas equation, <m>n</m> is equal to the number of moles (a unit of amount) of gas in the system. Before the reaction, the sodium azide is a solid, so there is no gas in the system. By reacting the sodium azide to create nitrogen gas, we add several moles of gas to the system. As we remember with the ideal gas law, the two sides of the <m>pV = nRT</m> equation have to balance, so by adding a bunch of moles of nitrogen gas, we force the volume of the system to increase dramatically. This inflates the airbag in between 20-40 milliseconds, giving it time to begin deflating before your head hits it. This disperses the force, dramatically improving chances of avoiding serious injury.<ref>http://www.scientificamerican.com/article/how-do-air-bags-work/</ref>

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