Sciencemadness Discussion Board - Synthesis of Ammonium Perchlorate

Synthesis of Ammonium Perchlorate

lordcookies24 - 30-12-2019 at 12:52

I plan on making Ammonium Perchlorate through the double decomposition reaction between Sodium Perchlorate and Ammonium Nitrate (or any other easy to find ammonium salts). To make Sodium Perchlorate, most online articles ask perform eletrolysis on hot(70C) aqueous Sodium Chlorate. To make Sodium Chlorate, I need to perform eletrolysis on hot(70c) aqueous Sodium Chloride. Either i am understanding it completely wrong but since making the Perchlorate and Chlorate require the excact same condition (eletrolysis of 70°C aqueous solution), shouldn't making Sodium Chlorate make Sodium Perchlorate as soon as it is produced? I read somewhere else that the best way to make Chlorates is through Pottasium Chloride since they don't disolve in water. So does Sodium Chlorate directly oxidize to Sodium Perchlorate without an extra step since it disolves in water? And will adding Ammonium Nitrate to a Sodium Perchlorate solution yield Ammonium Perchlorate? And for the final question are graphite eletrodes (from pencils) fine as long as I recrystalize the product or do I have to spend 60 bucks on platnium-titanium electrodes?

Fery - 31-12-2019 at 01:18

using graphite electrodes you can obtain only NaClO3, not NaClO4
it is possible to electrolytically cover graphite with a layer of PbO2 so then such electrode is capable to produce also ClO4- but Pb is toxic, while covering the electrode it must be rotating at high rpm (repulsive force >> bubbles adhesive force so the higher diameter of electrode and higher rpm the better) otherwise bubbles of gas cause defects in layer of PbO2 so fast corrosion when using defective electrode in ClO4- production
when you obtain NaClO3, carefully slowly melting it and heating produces NaCl + NaClO4 with side reaction of decomposition into NaCl+O2 (or total decomposition into NaCl+O2 without NaClO4 :mad:

if you overheat it) you can separate them using acetone (NaCl + NaClO3 insoluble, NaClO4 soluble)
do not try to produce K salts as KClO4 has very low solubility so you can't obtain NH4ClO4 from KClO4, you need NaClO4 which is more soluble in water than NH4ClO4
decades ago it was possible to buy a herbicide Travex in my country which was a mixture of 50:50 NaCl + NaClO3 but it is not produced anymore. It was sold in 1 kg tight well closed metallic tins and my grandma, God rest her soul, was always surprised how fast was it "leaking" and disappearing from the can

Wow some brave soul in my country started something like a private fight against restrictions and found a way how to sell legally NaClO3 to public - this seller is known to be friendly to young chemists - the shop sells NaClO3 phlegmatized with NaCl so concentration of NaClO3 is below 40% limit, this mixture is very close to my beloved Travex of my childhood

Bedlasky - 31-12-2019 at 06:42

Quote: Originally posted by Fery

That's really cool

. I know this seller - I bought from him twice some chemicals and met him personally in his shop. He is chemist on the first look

wg48temp9 - 1-1-2020 at 05:36

Below are graphs of the solubility of sodium potassium and ammonium perchlorates in water versus temperature. For comparison potassium chloride is also shown.

The graphs show how potassium perchlorate has approximatly 200 times less solubility than sodium perchlorate at 0C. .

The usual double decomposition synthesis requires that the target salt is insoluble or has the lowest solubility of the reactants and products of the decomposition at some temperature. As can be seen from the graphs ammonium perchlorate has three times the solubility of potassium perchlorate at any temperature hence water solutions can not be used to produce ammonium perchlorate from potassium perchlorate in the usual way.

woelen - 1-1-2020 at 10:07

If you can make sodium perchlorate, then it is easier to make ammonium perchlorate through HClO4. In order to do so, boil down the solution of NaClO4 (no need to really separate it) and add concentrated HCl (36% or so) in excess amount. This produces a lot of precipitate of NaCl and leaves HClO4 in solution. Any NaClO3 is destroyed in this way and also any NaCl is precipitated. What remains is a mixed solution of HClO4 and HCl, which also contains a little NaClO4. Boil down this liquid to appr. 150 C and then allow to cool. A little more NaCl may precipitate.

To this liquid add ammonia until the liquid smells of ammonia (you must have a little excess ammonia, otherwise you get a very hygroscopic product, which is hard to crystallize). Then allow the water to evaporate at a warm place. Do not let it evaporate to dryness, once you get a lot of crystals, covered in a thin layer of liquid, then decant the liquid and dry in filter paper. In this way you get fairly pure NH4ClO4 with only little sodium left in the product.

jderimig - 1-1-2020 at 16:21

If you have sodium perchlorate its even easier to add ammonium chloride (cheaper) to the solution. Cool and ammonium perchlorate will crystallize out.

The hard part is getting the sodium perchlorate. Also you must kill and sodium chlorate before the ion exchange reaction or you produce traces amounts of ammonium chlorate which extremely explosive and unstable.

woelen - 2-1-2020 at 01:21

Indeed, the hard part is getting NaClO4. But once you have that, the method through HCl is easier than the method through NH4Cl, even though it has more steps. The method through conc. HCl removes much more sodium ions and it destroys any chlorate, present in your NaClO4.

jderimig - 2-1-2020 at 09:41

In your process what happens to the excess HCL?

woelen - 2-1-2020 at 10:40

If you boil down the liquid to nearly 150 C then you drive off the HCl, while HClO4 remains behind (the water/HClO4 azeotrope boils at 220 C or so, while the water/HCl azeotrope boils below 120 C).

lordcookies24 - 2-1-2020 at 18:21

Thank you for all the comments guys, I have a lot more to go on. I guess buying Mixed Metal Oxide electrodes will be the way to go for this electrolysis.

symboom - 3-1-2020 at 01:56

Does hypochlorite react with ammonium nitrate
Does it make hydrazine nitrate
I know it reacts with ammonia and urea