Changes

The '''ideal gas law''', is an [[equation of state]] for an ideal gas. It combines three [[gas]] laws ([[Dalton's Law of Partial Pressures|Dalton's Law]], [[Boyle's Law]] and [[Charles' Law]]) into one equation:  

The '''ideal gas law''', is an equation of state for an ideal gas. It combines three [[gas]] laws ([[Dalton's Law of Partial Pressures|Dalton's Law]], [[Boyle's Law]] and [[Charles' Law]]) into one equation:  

:<math>PV = nRT</math>

:<math>PV = nRT</math>

*''T'' the absolute [[temperature]] (meaning it must be in [[Kelvin]] or [[Rankine]]);  

*''T'' the absolute [[temperature]] (meaning it must be in [[Kelvin]] or [[Rankine]]);  

*''n'' is the number of [[Mole (chemistry)|moles]] of the gas occupying the volume V;  

*''n'' is the number of [[Mole (chemistry)|moles]] of the gas occupying the volume V;  

*''R'' is the [[gas constant]].

*''R'' is the ideal gas constant.

The gas constant can be expressed in any number of units, but the most common representations are <math>0.0821\,L \cdot atm \cdot mole^{-1} \cdot K^{-1}</math> or <math>8.314\,J \cdot mole^{-1} \cdot K^{-1}</math>

The ideal gas constant can be expressed in any number of units, but the most common representations are <math>0.0821\,L \cdot atm \cdot mole^{-1} \cdot K^{-1}</math> or <math>8.314\,J \cdot mole^{-1} \cdot K^{-1}</math>

==Ideal Gas==

==Ideal Gas==

The equation is valid only for an ideal gas, the hypothetically perfect embodiment of a gas in which the particles ([[atom]]s or [[molecule]]s) in the gas are spherical, identical, have no [[volume]], and experience no intermolecular forces between them. All collisions between the particles or the particles and the container are perfectly [[elastic collision|elastic]].   

 

The equation is valid only for an ideal gas, the hypothetically perfect embodiment of a gas in which the particles ([[atom]]s or [[molecule]]s) in the gas are point particles (have no [[volume]]) and experience no intermolecular forces. All collisions between the particles or the particles and the container are perfectly elastic.   

Since this is just a model, real gases only obey the ideal gas law approximately, not perfectly. Generally, the ideal gas assumption is accurate for unreactive gases at high temperature and/or low pressure. A good rule of thumb is that the assumption can be used above room temperature and below 1 [[atmosphere]] of pressure.

Since this is just a model, real gases only obey the ideal gas law approximately, not perfectly. Generally, the ideal gas assumption is accurate for unreactive gases at high temperature and/or low pressure. A good rule of thumb is that the assumption can be used above room temperature and below 1 [[atmosphere]] of pressure.

==Density==

==Density==

With the molar mass (''M''), the ideal gas law can be used to calculate the [[density]] of a gas, ''d''.

With the molar mass (''M''), the ideal gas law can be used to calculate the [[density]] of a gas, <math>\rho</math>.

:<math>PM=dRT</math>

:<math>PM= \rho RT</math>

[[Category:Physics]]

[[Category:Physics]]

[[Category:Chemistry Laws and Principles]]

[[Category:Chemistry Laws and Principles]]