N2O production vs air distillation

After producing nitrogen by distilling air, how is that nitrogen used with the oxygen to yield nitrous oxide ($\ce{N2O}$)? I see $\ce{N2O}$ available in different purities from various suppliers, but how is that different from just distilling air? When distilling nitrogen from air, once both gasses have reached the right temp/pressure to become a liquid, what is preventing it from becoming $\ce{N2O}$ in a liquid form instead of one floating on top of the other? These questions are in reference to an automotive application.





> 
> After producing nitrogen by distilling air, how is that nitrogen used with the oxygen to yield nitrous oxide ($\ce{N2O}$)?
> 
> 
> 


It's not clear to me that $\ce{N2O}$ is produced from $\ce{N2}$: Rather, it appears that commercial quantities of $\ce{N2O}$ are produced by thermally decomposing ammonium nitrate:
$$\ce{NH4NO3(s) -> N2O(g) + 2H2O(g)}$$
as described (at least) by [this manufacturer and supplier of nitrous oxide gas plants](http://www.nitrousoxidegasplants.com/manufacturing-process.html). See the [comprehensive Wikipedia entry](https://en.wikipedia.org/wiki/Nitrous_oxide#Production) for more information.



> 
> I see $\ce{N2O}$ available in different purities from various suppliers, but how is that different from just distilling air?
> 
> 
> 


I'm not sure what you mean here.



> 
> When distilling nitrogen from air, once both gasses have reached the right temp/pressure to become a liquid, what is preventing it from becoming $\ce{N2O}$ in a liquid form instead of one floating on top of the other?
> 
> 
> 


Nitrogen is liquid in the range [63 to 77 K](https://en.wikipedia.org/wiki/Nitrogen); for oxygen, it's [54 to 90 K](https://en.wikipedia.org/wiki/Oxygen). Thus, the temperature range for which both are liquids is bounded by the range on nitrogen, or roughly between 63 and 77 K.


The temperature at which nitrous oxide solidifies (182 K per [Wikipedia](https://en.wikipedia.org/wiki/Nitrous_oxide)) is much higher than the temperature range at which oxygen and nitrogen are in the liquid phase, and thus it would have come out of solution as a solid long before the requisite temperature was reached. Thus, we would not expect to see liquid $\ce{N2O}$ co-existing with liquid oxygen and nitrogen.


Note bene: I am using the pressure range of 5 to 10 bars as cited [here](https://en.wikipedia.org/wiki/Air_separation) in assuming that liquid and solid phases of the above moieties do not coexist during industrial gas production at these relatively low pressures.


 4