How to separate a mixture of ammonium chloride and calcium carbonate?

Question

and how you will test that the ammonium chloride/calcium carbonate is pure?

Why you choose this method of separating(faster, more efficient, easier, cheaper, more accuate results)?

about Valentinehelle's answer
you can't tell wheather this sample is pure by just adding acid to the calcium carbonate sample, because as long as the sample contains some CaCO3, it will give off CO2 anyway.

about Valentinehelle's answer
you can't tell wheather this sample is pure by just adding sodium hydroxide, because as long as the sample contains some NH4Cl, it will give off CO2 anyway.
that's my point, not sure if is right. Can anyone help me?
PS: If we use filtering , how about the filtrate(NH4Cl solution), we need to also separate NH4Cl(solute) from the water(solvent). Can anyone suggest a further way?? :D

Answer 1

Calcium carbonate is virtually insoluble in water but Ammonium chloride is very soluble in water,

Therefore you can separate them by adding water to the mixture and filtering out the insoluble Calcium carbonate, leaving behind a solution of Ammonium Chloride.

You can test the purity of the ammonium chloride solution by adding an acid and seeing whether CO2 is produced.

You can test the purity of the Calcium carbonate by adding Sodium Hydroxide and seeing whether Ammonia gas is produced.

It is cheap, fast and easy.

Answer 2

sublimation. NH4Cl sublimes on heating so, you can heat it with a test tube hung over it and you will have NH4Cl is the overhanging tube. Cheap and is slow, then no CaCO3 is lost or contaminated.