math
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NH4NO3 synthesis from KNO3 and NH4HCO3
Hello,
I'd like to know how I could separate NH4NO3 from potassium bicarbonate produced by the following reaction in water.
KNO3 + NH4HCO3 -> NH4NO3 + KHCO3
Thank you 
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Poppy
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Hummm...
How would you separate the two by means of a simple displacement being so that potassium bicarbonate is highly soluble in water?
At least one product must have low solubility!
[Edited on 8-11-2012 by Poppy]
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weiming1998
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Quote: Originally posted by math  | Hello,
I'd like to know how I could separate NH4NO3 from potassium bicarbonate produced by the following reaction in water.
KNO3 + NH4HCO3 -> NH4NO3 + KHCO3
Thank you |
Your reaction does not work. KNO3 is less soluble than NH4NO3 and NH4HCO3 less soluble than KHCO3, so you can't crystallize the products out. In
solution, you have a mass of ions, which, in your case, are K+, NH4+, HCO3- and NO3-. When you try to crystallize a solution of such ions, the ions
which forms a comparatively less soluble salt joins and forms a solid, leaving the ions of the more soluble salt still dissociated in water. This is
how a double displacement reaction works. In your case, in such a solution of ions, NH4HCO3 will precipitate first, making your proposed double
displacement reaction impossible to achieve. Heating the solution will drive off the NH4HCO3 as NH3 and CO2, leaving only KNO3 in water.
Your reaction might be useful to make KNO3 from NH4NO3, but it can't make NH4NO3 from KNO3.
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vmelkon
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You have to convert your ammonia salt to a sulfate first and take advantage of K2SO4 low solubility.
K2SO4
12.0 g / 100 mL (25 °C)
(NH4)2SO4
74.4 g / 100 mL (20 °C)
KNO3
38.3 g / 100 mL (25 °C)
NH4NO3
150 g/100 mL (20 °C)
2 NH4HCO3 +H2SO4 -> (NH4)2SO4 + 2 H2O +2 CO2
then mix and cool down to solution as much as you can
2 KNO3 + (NH4)2SO4 -> K2SO4 + 2 NH4NO3
and filter out the solid K2SO4.
Your solution will still have dissolved K2SO4.
Leave the solution in a drying dish until all water is gone. Add anhydrous methanol. NH4NO3 dissolves but K2SO4 does not. I'm not sure if (NH4)2SO4
dissolves in methanol.
Anyway, filter again and dry it in a dish. You'll have NH4NO3 crystals.
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Poppy
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Waste a little more materials:
KNO3 + H2SO4 --> HNO3 + KHSO4
NH4HCO3 + NaOH --> NH3 + NaHCO3 + H2O
After prepare in gas phase reaction:
HNO3 + NH3 --> NH4NO3
Excesses of one of those will escape as gas. Profit: You have highly activated ammonium nitrate.
It's basically the same as evaporating reactions done in single jar
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ldanielrosa
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If you aren't committed to using the materials you already mentioned, you'll have a much easier time with Ca(NO3)2.5H2O and (NH4)2SO4. Both of these
should be available at an agriculture store.
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