Lion850
National Hazard
Posts: 517
Registered: 7-10-2019
Location: Australia
Member Is Offline
Mood: Great
|
|
Ceric Manganese Nitrate
I tried to make the double salt Ceric manganese nitrate
Mn[Ce(NO3)6.8H2O] but I honestly don’t know if I ended up with the correct stuff.
I struggled to get the equation into my Stoichiometry app, I could only get it to accept it by putting the Mn as a separate product to the Ce(NO3)6. I
did not think this split would have an effect on the app telling me the starting quantities. The procedure followed:
8.6g Mn(NO3)2.4H2O and 10g Ce(NO3)3.6H2O was placed in a small beaker and dissolved in a minimal amount of water. 15ml of 70% Nitric acid was added
and the mixture stirred. It was initially very pale pink but became more yellow as it boiled down on the hot plate. At low volume I transferred the
solution to a steam bath. After some hours on the steam bath no more fumes was seen to be coming off, it was a sticky liquid. The crucible was then
placed in the desiccated and high vacuum pulled. The mixture started to boil in slow motion; this did not stop after a while as I expected if water
was boiling off. I thought about the low melting points of nitrates (especially the manganese) and wondered whether at my ambient temp of around 35
the product itself was remaining liquid and boiling off under vacuum.
I then removed the crucible from the desiccator and placed it in ice water; the contents quickly solidified. Final product recovered (quite dry and
brittle) was 14.8g.
See photo attached, I wonder if this is the correct color? I could not find any info of this double salt online; color and melting point would be
handy to know.
|
|
|
woelen
Super Administrator
Posts: 7987
Registered: 20-8-2005
Location: Netherlands
Member Is Offline
Mood: interested
|
|
This can be anything. It can be your double salt, but it also can be just a mix of manganous nitrate and ceric nitrate, or even a mix of manganous
nitrate, ceric nitrate and cerous nitrate. The yellow color is a good indicator of the presence of at least some ceric ions, but without further
analysis it is not possible to say anything about this.
Actually, double salts in fact are not much more than mixes, the only thing is that with double salts, the different ions are present in some specific
stoichiometric ratios, because of the regular spatial arrangement of the different ions. But once the double salt is dissolved, it again separates
into separate ions and you cannot distinguish between a solution of the double salt and a solution of a mix of the two (or more) separate salts in
their specific stoichiometric ratio. E.g. if you dissolve 1 mole of K2SO4 and 1 mole of Al2(SO4)3 in a certain amount of of water, then you cannot
distinguish this from a solution of 1 mole of alum in that amount of water.
|
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
