Sciencemadness Discussion Board

sodium permanganate

bluamine - 13-7-2022 at 06:13

Hi everyone!
Guys who worked with sodium permanganate before?
Is it a good alternative fo potassium permanganate?

Tsjerk - 13-7-2022 at 07:02

It is a fine alternative for KMnO4 as long as you can keep it dry, as it is hygroscopic.

bluamine - 13-7-2022 at 12:42

Quote: Originally posted by Tsjerk  
It is a fine alternative for KMnO4 as long as you can keep it dry, as it is hygroscopic.

Well that's obvious and I guess it's similar to many sodium salts that are more hygroscopic than their respective potassium cautions like sodium/potassium nitrate.. Doesn't the hydrated form work as fine as the pre-dried form in an aqueous solution??!!

[Edited on 13-7-2022 by bluamine]

violet sin - 13-7-2022 at 16:27

I'd assume it would be fine to use hydrated material in an aqueous solution, but I've been wrong before. The headache I see is weighing the proper amount. You'd be guessing at the hydration level, so hopefully it's not super touchy about stoichiometry.

All seems straight forward, what kind of interactions would you imagine it would not work for? I mean if it's going into a pyro powder, that would not be fun.

woelen - 13-7-2022 at 22:31

I do not see it as a suitable alternative. I purchased NaMnO4 some years ago, but the material has decomposed. I now have an alkaline mix of MnO2, sodium oxide/hydroxide and probably some sodium carbonate as well. There still is some NaMnO4 in the mix, but I think more than half of it has decomposed.

On the other hand, KMnO4 is stable indefinitely. I still have some KMnO4, which I purchased more than 35 years ago, and it is as if I purchased it yesterday. A nice dry crystalline solid.

I bought my NaMnO4, because I had the opportunity (it is amazingly hard to get your hands on). It can be used to make much more concentrated solutions of permanganate, and it allows you to make other less soluble permanganates (e.g. ammonium permanganate, silver permanganate), but if you get some, then you should use it quickly.

Keras - 13-7-2022 at 23:37

An another advantage of sodium salts is that you get more bang for your bucks, since the molar mass is less…

bluamine - 14-7-2022 at 07:13

Quote: Originally posted by woelen  
I purchased NaMnO4 some years ago, but the material has decomposed.

Quote: Originally posted by woelen  

There still is some NaMnO4 in the mix, but I think more than half of it has decomposed.

Well, if it would take years to decompose, it would be just fine..
I guess you can remake it using sodium hypochlorite solution which may convert MnO2/NaOH mixture to NaMnO4, but you will have to separate NaCl then.. I have no idea how to do it since organic solvents can't be used to percepitate sodium chloride out..
Quote: Originally posted by woelen  

It can be used to make much more concentrated solutions of permanganate

I want to make some ethylene glycol, so I guess it would help me to make a concentrated and cold solution. I think also I'd better use it instead of potassium permanganate because I won't need to recycle sodium sulfate
Quote: Originally posted by Keras  
An another advantage of sodium salts is that you get more bang for your bucks, since the molar mass is less…

Yes that's one reason I want to use it for

Texium - 14-7-2022 at 10:10

Quote: Originally posted by Keras  
An another advantage of sodium salts is that you get more bang for your bucks, since the molar mass is less…
Except that you actually don’t, since NaMnO4 tends to be a lot more expensive than KMnO4, and you have to use it up before it turns into permanganate soup and/or degrades.
Quote: Originally posted by bluamine  

I want to make some ethylene glycol, so I guess it would help me to make a concentrated and cold solution.
Can you not get ethylene glycol based antifreeze where you live? Here it’s about $12 for a gallon/3.8 liters that just needs to be distilled to remove dye and corrosion inhibitors.

[Edited on 7-14-2022 by Texium]

Fantasma4500 - 19-7-2022 at 02:49

well one advantage manganate has over permanganate, is that manganate is doable to make melting NaOH with MnO2, were still struggling to make KMnO4
K2MnO4 would also be doable in similar fashion

Keras - 19-7-2022 at 04:16

Quote: Originally posted by Texium  
Except that you actually don’t, since NaMnO4 tends to be a lot more expensive than KMnO4, and you have to use it up before it turns into permanganate soup and/or degrades.


Can’t you turn NaMnO₄ into KMnO₄ by mixing it with KCl or KOH, for example? Ok, that has nothing to do with the price, just wondering.

bluamine - 21-7-2022 at 16:58

Quote: Originally posted by Texium  
Can you not get ethylene glycol based antifreeze where you live? Here it’s about $12 for a gallon/3.8 liters that just needs to be distilled to remove dye and corrosion inhibitors.

[Edited on 7-14-2022 by Texium]

I got some before, but since the commercial product contains other various other chemicals i guess it'd be a bad idea to extract it from antifreeze

bluamine - 21-7-2022 at 17:01

Quote: Originally posted by Keras  

Can’t you turn NaMnO₄ into KMnO₄ by mixing it with KCl or KOH, for example? Ok, that has nothing to do with the price, just wondering.

Well theotically you can, but how would you seperate substances since all of them are water soluble, and you likely can't use any organic solvents because they will react with permanganate ions

Keras - 21-7-2022 at 21:31

Quote: Originally posted by bluamine  

Well theotically you can, but how would you seperate substances since all of them are water soluble, and you likely can't use any organic solvents because they will react with permanganate ions

Solubility is readily different: I read 900 g/L for sodium permanganate (!) vs 76 g/L for potassium permanganate, which is not even the tenth. Under those conditions, any well-conducted recrystallisation should give you almost pure KMnO₄.

bluamine - 22-7-2022 at 07:30

Quote: Originally posted by Keras  

Solubility is readily different: I read 900 g/L for sodium permanganate (!) vs 76 g/L for potassium permanganate, which is not even the tenth. Under those conditions, any well-conducted recrystallisation should give you almost pure KMnO₄.

I know KMnO4 wouldn't be a problem since it's not very soluble,by I guess one should consider other salts, like NaOH & NaCl which is very soluble (NaCl: 316g/l if I'm not wrong)

draculic acid69 - 25-7-2022 at 21:15

Unless you are using it for a specialised synthesis I don't see how it would benefit you.
Sounds like reinventing the wheel to me just to arrive at ethylene glycol.
If it's about the journey I get it but if it's not then you should just distill the radiator coolant