An interesting simple approach would be to just add vinegar to CaCO3 until CO2 bubbling stops. This produces aqueous calcium acetate which, by
heating, one can concentrate without decomposition (unlike aqueous ammonium acetate). Add a source of NH3 (one could just place a beaker of
concentrated calcium acetate, which is shaken or stirred, in a larger sealed vessel containing household ammonia). Freeze and defrost to aid in
letting the Ca(OH)2 settle out of solution (or use more sophisticated equipment). Decant leaving concentrated aqueous ammonium acetate.
Following drying procedures described previously.
Note, one could concentrate the calcium acetate to the point of a moist salt/wet slurry. Treat the cold wet calcium acetate with an excess of NH3, and
then with hot CH3OH dissolving any formed ammonium acetate. Filter or distill off the latter hot methanol and ammonium acetate mix (see solubility in
hot methanol, which apparently sharply rises, per Wikipedia at https://en.m.wikipedia.org/wiki/Ammonium_acetate).
Also, in place of CaCO3, one can employ MgCO3. The latter can be formed, as I done on several occasion, as a MgCO3 white precipitate from the action
of NaHCO3 on heating (decomposing unstable aqueous Mg(HCO3)2) aqueous MgSO4 (Epsom Salts is sold in supermarkets, drug stores,..).
[Edit] This differs from the prior suggestion of NH3 and dilute acetic acid as it reduces the amount of problematic water present at the expense of
dealing with a Ca(OH)2 suspension (or not, per note above).
[Edited on 5-8-2017 by AJKOER]
[Edited on 5-8-2017 by AJKOER] |
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