Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Manganese Heptoxide + Nitromethane = Nothing?!
Rhodanide
National Hazard
****




Posts: 340
Registered: 23-7-2015
Location: VHS Land
Member Is Offline

Mood: That retro aesthetic

shocked.gif posted on 16-3-2017 at 06:14
Manganese Heptoxide + Nitromethane = Nothing?!


So, yesterday I tried combining small amounts of manganese heptoxide and Nitromethane. Prepared & aware of the risks, I put the two together... and...
nothing. Absolutely nothing. My Nitromethane is 99% pure, bought from a supplier. Nor was my heptoxide to blame, it combusted or even detonated everything else I put in it (I'm looking at you, Hexamine!).
Maybe a few bubbles were seen, but no flames, no MnO2 smoke, no sound, NOTHING!
Why?
Is there something obvious I'm missing? This is quite interesting to me.
View user's profile View All Posts By User
chornedsnorkack
National Hazard
****




Posts: 320
Registered: 16-2-2012
Member Is Offline

Mood: No Mood

[*] posted on 16-3-2017 at 23:20


Quote: Originally posted by Tetra  
Nor was my heptoxide to blame, it combusted or even detonated everything else I put in it (I'm looking at you, Hexamine!).

Did you try alkanes?
View user's profile View All Posts By User
woelen
Super Administrator
*********




Posts: 6940
Registered: 20-8-2005
Location: Netherlands
Member Is Offline

Mood: interested

[*] posted on 16-3-2017 at 23:44


Sometimes, two chemicals which are expected to be reactive towards each other, do not react. One thing, needed for spontaneous and exothermic reaction is that the energy contents of the end products is much lower than the energy contents of the starting materials, but the other thing, which is needed, is the presence of a pathway from the starting materials to the end materials.

Mn2O7, combined with many organics, including CH3NO2, has a lot of energy, so requirement 1 is met. Apparently, there is some difficultly going from the reactants to the end products. Higher temperature can make certain pathways possible. Catalysts can create completely new pathways, which may be easier to travel. Catalysts do not add more energy. I think that with Mn2O7+CH3NO2 gentle heating already may make a large difference.

Try heating a petri dish or hour glass to 100 C or so (in an oven). Quickly take this out of the oven, put one or two drops of CH3NO2 on it (by that time it will have cooled down to well below 100 C), and then add a drop of Mn2O7. I expect it to set off in that case.




The art of wondering makes life worth living...
Want to wonder? Look at https://woelen.homescience.net
View user's profile Visit user's homepage View All Posts By User
Tdep
National Hazard
****




Posts: 468
Registered: 31-1-2013
Location: Fixed Lasers
Member Is Offline

Mood: *laser noises*

[*] posted on 17-3-2017 at 01:21


I can vouch for this reaction not working. I tried it expecting big results but nothing. Manganese heptoxide made by the same method on the same day set fire to ethanol and toluene instantly
View user's profile View All Posts By User
Rhodanide
National Hazard
****




Posts: 340
Registered: 23-7-2015
Location: VHS Land
Member Is Offline

Mood: That retro aesthetic

[*] posted on 17-3-2017 at 04:49


Quote: Originally posted by chornedsnorkack  
Quote: Originally posted by Tetra  
Nor was my heptoxide to blame, it combusted or even detonated everything else I put in it (I'm looking at you, Hexamine!).

Did you try alkanes?


Negative.
Here are the results of what I threw in:
Hexamine: Detonation
Tetrachloroethylene: A violent, angry hissing noise
Guanidine Nitrate: A few pops, but not much else.
Nitrocellulose: Normal combustion/deflagration
Nitroguanidine: Nothing, but it was wet and very cold, which made this more or less understandable.
Hydrazine in EtOH: Extremely violent combustion
Sawdust: Combustion
Citric Acid: Excessive popping and flames
Ascorbic acid: Same as citric
Sulfur: Delayed detonation
Methanol: Combustion
Heating the Mn2O7: Decomposition.
View user's profile View All Posts By User
Rhodanide
National Hazard
****




Posts: 340
Registered: 23-7-2015
Location: VHS Land
Member Is Offline

Mood: That retro aesthetic

[*] posted on 17-3-2017 at 04:52


Quote: Originally posted by Tdep  
I can vouch for this reaction not working. I tried it expecting big results but nothing. Manganese heptoxide made by the same method on the same day set fire to ethanol and toluene instantly


I could absolutely see you doing that. For a moment, the thought "Acetone Peroxide and Manganese heptoxide" crossed my mind, but that thought was quickly shut out for obvious reasons.
I'm not messing with that shit ever again. Nor HMTD,
and ESPECIALLY NOT MEKP. HATE IT.
View user's profile View All Posts By User
Rhodanide
National Hazard
****




Posts: 340
Registered: 23-7-2015
Location: VHS Land
Member Is Offline

Mood: That retro aesthetic

[*] posted on 17-3-2017 at 04:54


Quote: Originally posted by woelen  
Sometimes, two chemicals which are expected to be reactive towards each other, do not react. One thing, needed for spontaneous and exothermic reaction is that the energy contents of the end products is much lower than the energy contents of the starting materials, but the other thing, which is needed, is the presence of a pathway from the starting materials to the end materials.

Mn2O7, combined with many organics, including CH3NO2, has a lot of energy, so requirement 1 is met. Apparently, there is some difficultly going from the reactants to the end products. Higher temperature can make certain pathways possible. Catalysts can create completely new pathways, which may be easier to travel. Catalysts do not add more energy. I think that with Mn2O7+CH3NO2 gentle heating already may make a large difference.

Try heating a petri dish or hour glass to 100 C or so (in an oven). Quickly take this out of the oven, put one or two drops of CH3NO2 on it (by that time it will have cooled down to well below 100 C), and then add a drop of Mn2O7. I expect it to set off in that case.


Good info, woe, thanks! :D
The beaker was in the snow, but not for long. I would think that the reaction of KMnO4 and H2SO4 would generate at least some heat, but as I said, it was in snow. I added some snow to precipitate the Heptoxide which likely cooled the soln. down as well.
View user's profile View All Posts By User
mayko
International Hazard
*****




Posts: 985
Registered: 17-1-2013
Location: Carrboro, NC
Member Is Offline

Mood: anomalous

[*] posted on 17-3-2017 at 07:00


Quote: Originally posted by Tetra  


I could absolutely see you doing that. For a moment, the thought "Acetone Peroxide and Manganese heptoxide" crossed my mind, but that thought was quickly shut out for obvious reasons.


These two do exactly what one would expect when they meet.








.... stop judging me ....




al-khemie is not a terrorist organization
"Chemicals, chemicals... I need chemicals!" - George Hayduke
"Wubbalubba dub-dub!" - Rick Sanchez
View user's profile Visit user's homepage View All Posts By User
Rhodanide
National Hazard
****




Posts: 340
Registered: 23-7-2015
Location: VHS Land
Member Is Offline

Mood: That retro aesthetic

[*] posted on 23-3-2017 at 05:32


Quote: Originally posted by mayko  
Quote: Originally posted by Tetra  


I could absolutely see you doing that. For a moment, the thought "Acetone Peroxide and Manganese heptoxide" crossed my mind, but that thought was quickly shut out for obvious reasons.


These two do exactly what one would expect when they meet.








.... stop judging me ....



Yeeeeeaaaahhh...
Not gonna try that LOL
View user's profile View All Posts By User
Sulaiman
International Hazard
*****




Posts: 2708
Registered: 8-2-2015
Location: Walsall UK but on extended Holiday in Malaysia
Member Is Offline


[*] posted on 23-3-2017 at 05:58


or, on the assumption that activation energy is the problem,
mix the manganese heptoxide and nitromethane
then add a drop or piece of one of the substances that does react vigorously with Mn2O7.




CAUTION : Hobby Chemist, not Professional or even Amateur
(suffering from separation of me and my chemistry stuff)
View user's profile View All Posts By User
Melgar
Anti-Spam Agent
*******




Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline

Mood: Estrified

[*] posted on 23-3-2017 at 13:01


Why is everyone so surprised that they don't react? Essentially, you're mixing two oxidizers. Or rather, an oxidizer with a molecule that's highly oxidized on one side, and an alkane on the other side. IIRC, nitromethane can only be oxidized by free-radical pathways, which would be above the temperature at which Mn2O7 decomposes.
View user's profile View All Posts By User
feacetech
Hazard to Others
***




Posts: 163
Registered: 12-2-2007
Member Is Offline

Mood: No Mood

[*] posted on 26-3-2017 at 14:04


Mn2O7 is a dangerous beast and not always predictable

I remember playing with it I was dripping very small drips onto processed bone dust (think bone component of blood and bone) with a very fine glass dropper

sometimes it would burn, sometimes smoulder

but on the odd occasion it would have an ear splitting crack.
View user's profile View All Posts By User
Rhodanide
National Hazard
****




Posts: 340
Registered: 23-7-2015
Location: VHS Land
Member Is Offline

Mood: That retro aesthetic

[*] posted on 27-3-2017 at 06:21


Quote: Originally posted by feacetech  
Mn2O7 is a dangerous beast and not always predictable

I remember playing with it I was dripping very small drips onto processed bone dust (think bone component of blood and bone) with a very fine glass dropper

sometimes it would burn, sometimes smoulder

but on the odd occasion it would have an ear splitting crack.


...Bone dust? Doesn't seem it would have much energy potential...
View user's profile View All Posts By User
feacetech
Hazard to Others
***




Posts: 163
Registered: 12-2-2007
Member Is Offline

Mood: No Mood

[*] posted on 27-3-2017 at 17:45


yea that's what I thought, it did have a small amount of fat in it but not much (1%) lots of ash and next to no nitrogen
View user's profile View All Posts By User
Melgar
Anti-Spam Agent
*******




Posts: 2004
Registered: 23-2-2010
Location: Connecticut
Member Is Offline

Mood: Estrified

[*] posted on 27-3-2017 at 18:42


Quote: Originally posted by feacetech  
yea that's what I thought, it did have a small amount of fat in it but not much (1%) lots of ash and next to no nitrogen


Carbon, from the protein (collagen and keratin, I think) that holds the bone together.
View user's profile View All Posts By User
Rhodanide
National Hazard
****




Posts: 340
Registered: 23-7-2015
Location: VHS Land
Member Is Offline

Mood: That retro aesthetic

[*] posted on 28-3-2017 at 06:39


Quote: Originally posted by Melgar  
Quote: Originally posted by feacetech  
yea that's what I thought, it did have a small amount of fat in it but not much (1%) lots of ash and next to no nitrogen


Carbon, from the protein (collagen and keratin, I think) that holds the bone together.


Well, regardless... It probably has not only minerals in it as well as water which I would think would both slow down any other reactions occurring.
Who knows, I may be wrong. :]
I've never tried this so I'm just going off of what I'd think would happen :D
View user's profile View All Posts By User

  Go To Top