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Author: Subject: Synthesis of alkali/alkaline earth peroxide by disproportionation
John paul III
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smile.gif posted on 28-4-2018 at 11:41
Synthesis of alkali/alkaline earth peroxide by disproportionation


It's possible to synthesize alkali peroxides by disproportionation of oxides i.e. to make K2O -> K2O2 +K at around 450°C. Is it possible to do something similiar with CaO? Also, is there an easy and low temp way to convert KOH to K2O?

[Edited on 28-4-2018 by John paul III]

[Edited on 28-4-2018 by John paul III]
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Rhodanide
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[*] posted on 30-4-2018 at 07:05


Quote: Originally posted by John paul III  
It's possible to synthesize alkali peroxides by disproportionation of oxides i.e. to make K2O -> K2O2 +K at around 450°C. Is it possible to do something similiar with CaO? Also, is there an easy and low temp way to convert KOH to K2O?

[Edited on 28-4-2018 by John paul III]

[Edited on 28-4-2018 by John paul III]



I'm not sure about KOH, but I DO know that I once saw a video about a guy who made K2O from heating the shit out of K2CO3.




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urea1990
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[*] posted on 30-4-2018 at 08:23


K2O + H2O ⇌ 2KOH

Edit: I've looked at the relative heat of formation for this reaction, and no amount of heat will decompose 2KOH into K2O and H2O.

2 moles of the hydroxide (ΔHf = -425 kJ/mol) can be formed from the oxide (ΔHf = -361 kJ/mol) and H2O (ΔHf = -242 kJ/mol); this means the hydroxide reaction is vastly favoured over the backwards reaction. In fact, no amount of heating of the hydroxide will form the oxide plus H2O - that reaction is just pushing it far too far up the entropic cliff, so to speak.

[Edited on 30-4-2018 by urea1990]
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John paul III
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[*] posted on 30-4-2018 at 11:36


Quote: Originally posted by Rhodanide  
Quote: Originally posted by John paul III  
It's possible to synthesize alkali peroxides by disproportionation of oxides i.e. to make K2O -> K2O2 +K at around 450°C. Is it possible to do something similiar with CaO? Also, is there an easy and low temp way to convert KOH to K2O?

[Edited on 28-4-2018 by John paul III]

[Edited on 28-4-2018 by John paul III]


I'm not sure about KOH, but I DO know that I once saw a video about a guy who made K2O from heating the shit out of K2CO3.

Was it done with a lab gas burner or in a foundry of sorts? Theoretically teclu burner would give the right temperature (but reality often differs with heat sources)
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Rhodanide
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[*] posted on 1-5-2018 at 05:30


Quote: Originally posted by John paul III  
Quote: Originally posted by Rhodanide  
Quote: Originally posted by John paul III  
It's possible to synthesize alkali peroxides by disproportionation of oxides i.e. to make K2O -> K2O2 +K at around 450°C. Is it possible to do something similiar with CaO? Also, is there an easy and low temp way to convert KOH to K2O?

[Edited on 28-4-2018 by John paul III]

[Edited on 28-4-2018 by John paul III]


I'm not sure about KOH, but I DO know that I once saw a video about a guy who made K2O from heating the shit out of K2CO3.

Was it done with a lab gas burner or in a foundry of sorts? Theoretically teclu burner would give the right temperature (but reality often differs with heat sources)


It needed a stupid amount of heat, from what I can remember. The guy used the arc from a MOT, here's the link to the vid: https://www.youtube.com/watch?v=tY5Qa-qrd3Y




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fusso
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[*] posted on 5-5-2018 at 21:24


Quote: Originally posted by Rhodanide  
Quote: Originally posted by John paul III  
Quote: Originally posted by Rhodanide  
Quote: Originally posted by John paul III  
It's possible to synthesize alkali peroxides by disproportionation of oxides i.e. to make K2O -> K2O2 +K at around 450°C. Is it possible to do something similiar with CaO? Also, is there an easy and low temp way to convert KOH to K2O?

[Edited on 28-4-2018 by John paul III]

[Edited on 28-4-2018 by John paul III]


I'm not sure about KOH, but I DO know that I once saw a video about a guy who made K2O from heating the shit out of K2CO3.

Was it done with a lab gas burner or in a foundry of sorts? Theoretically teclu burner would give the right temperature (but reality often differs with heat sources)


It needed a stupid amount of heat, from what I can remember. The guy used the arc from a MOT, here's the link to the vid: https://www.youtube.com/watch?v=tY5Qa-qrd3Y


Whats MOT?




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Bert
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5-5-2018 at 22:45
Diachrynic
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[*] posted on 6-5-2018 at 00:03


A MOT is a Microwave Oven Transformer. They're the reason a lot of people take apart microwaves, despite MOT's being extremely dangerous if you're not careful.

https://mad-science.wonderhowto.com/how-to/turn-microwave-ov...

You can make high voltage or high amperage with these, whatever ya need.




we apologize for the inconvenience
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