Methods of synthesis of nitrous oxide

The chem­i­cal com­pound known as ni­trous ox­ide (N₂0) be­came world-fa­mous thanks to a pop­u­lar film about street rac­ers. Do you re­mem­ber why they used this col­or­less, non-flammable gas, which has a pleas­ant sweet smell and taste? That’s right, so they could ac­cel­er­ate be­fore the fin­ish line. But in real life it’s best not to do this, as this sub­stance is dan­ger­ous. How­ev­er, there are many cas­es where ni­trous ox­ide can be also be used for good pur­pos­es.

What in­gre­di­ents will be re­quired to ob­tain ni­trous ox­ide (N₂0)?

• Lyophilized am­mo­ni­um ni­trate NH₄NO₃ (or sul­fam­ic acid and 73% ni­tric acid);
• Chem­i­cal ves­sels in which all these ex­per­i­ments will be car­ried out – flasks, re­torts and a burn­er;
• An elec­tri­cal heat­ing de­vice which can reg­u­late the tem­per­a­ture.

A pre­cise step-by-step al­go­rithm of the syn­the­sis of ni­trous ox­ide (N₂0)

All the re­ac­tions re­quired for the syn­the­sis of this sub­stance should be car­ried out ex­clu­sive­ly in a spe­cial­ly equipped chem­i­cal lab­o­ra­to­ry, as this process is not safe. Ad­di­tion­al­ly, all safe­ty rules must be fol­lowed – the ven­ti­la­tion must be turned on and a fire-ex­tin­guish­er should be at hand.

The most com­mon method

In the ma­jor­i­ty of cas­es ni­trous ox­ide, N₂O, is ob­tained by the ther­mal de­com­po­si­tion of dry am­mo­ni­um ni­trate, NH₄NO₃. In the chem­i­cal lab­o­ra­to­ry, ni­trous ox­ide can be ob­tained by heat­ing dry am­mo­ni­um ni­trate in­tense­ly with an elec­tri­cal de­vice (up to 270 de­grees Cel­sius). In fact, am­mo­ni­um ni­trate NH₄NO₃ is a well-known sub­stance that is not only used as a fer­til­iz­er, but also as an ex­plo­sive. For this rea­son, it must be em­pha­sized that the heat­ing tem­per­a­ture should not be above 270 de­grees Cel­sius – oth­er­wise a fa­tal ex­plo­sion is guar­an­teed. Again, in the process of heat­ing lyophilized am­mo­ni­um ni­trate NH₄NO₃, nec­es­sary con­di­tions are ven­ti­la­tion, cool­ing and col­lec­tion of the col­or­less N₂O gas in a sep­a­rate con­tain­er. It should be clear by now that the great­est dan­ger in this case is the ex­plo­sive na­ture of am­mo­ni­um ni­trate. So think once again about whether you re­al­ly need ni­trous ox­ide or not.

Al­ter­na­tive method

We should also look at an­oth­er method of ob­tain­ing ni­trous ox­ide N₂0 – ther­mal treat­ment by sul­fam­ic acid with 73% ni­tric acid in the same con­di­tions de­scribed in the first case. But bear in mind that this method is used pri­mar­i­ly in in­dus­try – the ma­te­ri­al ex­pens­es are sev­er­al times low­er, but the dan­ger is much greater (even de­spite the ex­plo­sive na­ture of am­mo­ni­um ni­trate). So you should cer­tain­ly not at­tempt to ob­tain ni­trous ox­ide in this way at home. This is be­cause sul­fam­ic acid can burn the skin and mu­cous mem­branes, and ni­tric acid it­self and its fumes are high­ly tox­ic: they cause ir­ri­ta­tion to the up­per and low­er res­pi­ra­to­ry tracts, while HNO₃ it­self dam­ages all the lay­ers of the skin, form­ing sores that are dif­fi­cult to treat. Here you'll find a lot of in­ter­est­ing re­ac­tions with ni­tro­gen.

Stor­ing the ob­tained com­pound

There is an­oth­er fac­tor that you should take into ac­count – N₂0 gas only moves to a liq­uid state un­der a pres­sure of at least 40 at­mos­pheres at room tem­per­a­ture. Ob­vi­ous­ly, this is dif­fi­cult to achieve at home, to put it mild­ly.

The eas­i­est way to solve the prob­lem

You shouldn’t risk the life and health of oth­ers for a few liters of laugh­ing gas. As ni­trous ox­ide is used as an in­haled anes­thet­ic, it can be pur­chased from phar­ma­ceu­ti­cal com­pa­nies. As N₂0 is not a nar­cot­ic sub­stance, there will not be any prob­lems in buy­ing it.