AlphaDecay - 20-3-2014 at 11:09
I have been searching everywhere on the internet about this reaction:
2KNO3 + [NH4]2SO4 -> K2SO4 + 2NH4NO3
Since potassium sulfate is less soluble (111g/L - 20 degrees celsius) than potassium nitrate (316g/L - 20 degrees celsius), could this metathesis
reaction happen?
Zyklon-A - 20-3-2014 at 11:24
Yes,but I would suggest dissolving your potassium nitrate in the minimal amount of hot water. Then pour that into the stoichiometric amount
of ammonium sulfate in equally hot water, to drive the equilibrium completely to the right.
The solubility of [NH4]2SO4 in hot water doesn't change too much: 241 g/L, vs. KNO3: 1410g/L at 100°C.
[Edited on 20-3-2014 by Zyklonb]
Dr.Bob - 20-3-2014 at 12:17
And NH4NO3 is quite soluble, so if you filter off the first crop of K2SO4, then you may be able to let it sit a few days and evaporate a bit and then
filter off (or decant away the liquid) yet more K2SO4 to continue the reaction further to the right.
From "The purification of lab chemicals" book:
"NH4NO3 can be recrystallized from distilled water (1 g/ml) by adding EtOH or from warm water (1g/0.5 ml) by cooling with an ice/salt bath."
[Edited on 20-3-2014 by Dr.Bob]
*FWOOSH* - 20-3-2014 at 14:47
I was doing something similar with calcium nitrate and ammonium sulphate, both cheap as hell and I think calcium sulphate is going to be a lot easier
to remove.
Zyklon-A - 20-3-2014 at 14:54
Yep, calcium sulfate will be much easier to seperate as it will immediately precipitate.
AlphaDecay - 20-3-2014 at 15:27
Ok, thanks for your help.