I want to make $\ce{N2O}$ in my school chem lab.

I'm thinking of making it from $\ce{Zn_{(s)}}$ in $\ce{HNO3_{(dil)}}$ :

$$\ce{ Zn_{(s)} + HNO3_{(dil)} -> N2O + Zn(NO3)2 + H2O }$$

I'm not able to get $\ce{Zn_{(s)}}$, so I would like to make it on my own in lab.

  • $\begingroup$ This might help (without zinc): chemistry.about.com/b/2013/07/27/… $\endgroup$ – Devashish Das Aug 18 '14 at 8:34
  • $\begingroup$ Zinc is cheap and readily available. Making it is most likely much harder than the reaction you want to use it for (even if that is the best way to achieve your goal.) Most labs and lab suppliers will have it. Unless you want to set up a metal foundry which seems overambitious to obtain something you can buy off the shelf. $\endgroup$ – matt_black Aug 19 '14 at 11:44

Ahem, forget it.

Theoretically speaking, you can get $\ce{Zn}$ from alkaline batteries (see details here), but you have no chance to get pure $\ce{N2O}$ this way and reaction may easily go out of control.

Attention! Detonation hazard !!!

The usual and easy way to produce $\ce{N2O}$ is to heat very carefully widely available $\ce{NH4NO3}$, to $180-200~^\circ\mathrm{C}$. It is an absolute imperative to keep temperature of the reaction mixture below $240~^\circ\mathrm{C}$. Decomposition of ammonia nitrate ($\ce{NH4NO3}$) is exothermic and may proceed explosively. To be on the safe side, use sand bath to heat the reaction flask and put thermometer into the sand, so its temperature never risen above safe limits. Liquid bath with appropriate liquid may be better, but I'm not sure if a school lab would have proper liquid (silicone oil with high flash point). The produced gases should be cooled in Liebig condenser to separate water, and $\ce{N2O}$ may be further dried with $\ce{H2SO4}$. Of course, all joints must be sealed using proper oil. And keep a bath of cold water to cool the reaction mixture in case if temperature raises above safe limits.

It is advised to use lab grade, not fertilized grade ammonia nitrate.

Possible safer, but costlier route

It is reported that it is possible to produce $\ce{N2O}$ by heating mixture of $5~\mathrm{mL}$ $6~\mathrm{M}~\ce{HNO3}$, $1~\mathrm{g}~\ce{NH4NO3}$ and $0.05~\mathrm{g}~\ce{NaCl}$ on water bath at $\approx 80~^\circ\mathrm{C}$. If this works, it is a safer route, as hot ammonia nitrate is diluted and autospeeding reaction cannot occur. Link

  • 1
    $\begingroup$ C'mon folks, can we call it ammonium nitrate instead of ammonia nitrate? $\endgroup$ – iad22agp Aug 18 '14 at 15:54
  • 1
    $\begingroup$ If I edit the post, nobody learns anything. If you are going to succeed in chemistry, you have to learn correct nomenclature. $\endgroup$ – iad22agp Aug 19 '14 at 1:03

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