Mixell
Hazard to Others
Posts: 449
Registered: 27-12-2010
Member Is Offline
Mood: No Mood
|
|
NaNO3 decomposition
I found the following reaction on the internet:
2NaNO3----> 2NaNO2 +O2
But the problem is that NaNO2 got a lower decomposition temperature than NaNO3.
So what will NaNO2 decompose to?
May be the reaction will be as following: 2NaNO2---->Na2O +N2O +O2?
Or the products will be Na2O + NO2 + NO?
|
|
|
ScienceSquirrel
International Hazard
Posts: 1863
Registered: 18-6-2008
Location: Brittany
Member Is Offline
Mood: Dogs are pets but cats are little furry humans with four feet and self determination! 
|
|
Not in my experience.
I have made small amounts of sodium nitrite by heating the nitrate until it liquifies and then keeping it liquid until gas evolution slmost ceases.
There is a video here;
http://www.youtube.com/watch?v=L7qRoYQEBPk
|
|
|
Mixell
Hazard to Others
Posts: 449
Registered: 27-12-2010
Member Is Offline
Mood: No Mood
|
|
Well, I just did that (I think), a white solid has formed, did you received the same results?
|
|
|
Mixell
Hazard to Others
Posts: 449
Registered: 27-12-2010
Member Is Offline
Mood: No Mood
|
|
On another topic, is it possible to isolate K2MnO4 from a 1:1 mole mix of K2MnO4 and MnO2?
May be it will be soluble in ethanol?
|
|
|
ScienceSquirrel
International Hazard
Posts: 1863
Registered: 18-6-2008
Location: Brittany
Member Is Offline
Mood: Dogs are pets but cats are little furry humans with four feet and self determination!
|
|
It is pretty much white solid to white solid so it is hard to tell if you heated it hard enough.
Heating it too hard will result in brown fumes and the product will be very strongly alkaline when dissolved in water.
Tests for nitrite are here;
http://en.labs.wikimedia.org/wiki/Inorganic_Chemistry/Qualit...
|
|
|
ScienceSquirrel
International Hazard
Posts: 1863
Registered: 18-6-2008
Location: Brittany
Member Is Offline
Mood: Dogs are pets but cats are little furry humans with four feet and self determination!
|
|
Quote: Originally posted by Mixell  | On another topic, is it possible to isolate K2MnO4 from a 1:1 mole mix of K2MnO4 and MnO2?
May be it will be soluble in ethanol? |
Potassium permanaganate is soluble in water and crystallises well, manganese dioxide is completely insoluble.
|
|
|
Mixell
Hazard to Others
Posts: 449
Registered: 27-12-2010
Member Is Offline
Mood: No Mood
|
|
Brown fumes did not appear, but oxygen gas was formed (I did everything exactly as you).
potassium manganate (K2MnO4) reacts with water to form MnO2 and KMnO4...
|
|
|
Mixell
Hazard to Others
Posts: 449
Registered: 27-12-2010
Member Is Offline
Mood: No Mood
|
|
double post
[Edited on 6-1-2011 by Mixell]
|
|
|
ScienceSquirrel
International Hazard
Posts: 1863
Registered: 18-6-2008
Location: Brittany
Member Is Offline
Mood: Dogs are pets but cats are little furry humans with four feet and self determination!
|
|
| Quote: Originally posted by Mixell | Brown fumes did not appear, but oxygen gas was formed (I did everything exactly as you).
potassium manganate (K2MnO4) reacts with water to form MnO2 and KMnO4... |
I would guess that you have a solid containing sodium nitrite then, you just have to test it.
Sorry my fault, you are talking about potassium manganate not potassium permanganate.
It can be prepared in aqueous solution and crystallised from aqueous solution.
It should be noted that the manganate ion is stable in alkaline solution while the permanganate ion is stable in acid solution.
Oops, forgot the reference;
http://en.wikipedia.org/wiki/Potassium_manganate
[Edited on 6-1-2011 by ScienceSquirrel]
|
|
|
unionised
International Hazard
Posts: 5109
Registered: 1-11-2003
Location: UK
Member Is Offline
Mood: No Mood
|
|
I suspect potassium manganate will oxidise alcohol rapidly.
Water will dissolve the manganate but not MnO2. Some will disproportionate so you might get a better yield by adding KOH to the water first.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
