dann2 - 16-6-2007 at 15:30
Hello,
Has anyone any info. on the solubilities of Ammonium Molybdate in Alcohols. I need to dissolve Tin (II) Chloride and Ammonium Molybdate but the Tin
Cl. will not dissolve without a reaction with the water. It will dissolve OK in Methanol but the Ammonium Moly will not.
Are there any solvents that will dissolve both.
The Ammonium Molybdate is difficult to dissolve in water actually. It seems to leave an insoluble ppt.
Could I add HCl to the water, this will help stop the Tin Cl reaction with the water, or perhaps I could use concentrated HCl altogether as the
solvent for both.
Is Ammonium Moly compatable with HCl.
The solubility of Ammonium Moly. I have read is about 43 grams per 100cc water but it decomposes if the water is warm.
http://www.todiniandco.com/products/molybdenum/ammonium_moly...
What ions do you get when you dissolve Ammonium Moly.
TIA,
Dann2
Rosco Bodine - 17-6-2007 at 00:16
The tin chloride could be in HCl to prevent hydrolysis .
And the ammonium molybdate could be in aqueous ammonia .
I think you will have to keep these separate ,
as even if you find a solvent for both , when
mixed together what you will probably get is precipitate
of tin molybdate and ammonium chloride .
not_important - 17-6-2007 at 07:09
If in highly alkaline solution you can have the molybdate ion, MoO4(-2). These condense and/or polymerize in less alkaline conditions giving various
poly-molybdates, of which "ammonium molybdate" is an example. The slowly dissolving and insoluble parts of ammonium molybdate are likely molybdic
acid.
I think you'll need to go to other salts to get a mixed solution. For tin try the tatrate, or the mixed ammonium tin tartrate. With the molybdate,
take a small amount into solution and try adding sugar to it to see if the precipitate dissolves; I believe that molybdic acid form complexes with
sugars like boric acid does. Or just add some aqueous ammonia.
Sodium molybdate and sodium stannite or stannate are other possibilities, although stannites are not stable so the solution would need to be used
quickly. Another is thiomolybdate and thiostannate.
There might even be a hetero-poly-acid from molybdenum and tin, although I'm a bir doubtful on this.