Separation of mixture?

Question

In lab today, we separated a mixture of ammonium chloride, salt, and sand by heating the mixture, subliming the ammonium chloride, then adding water to the sand and salt and decanting to remove the salt from the sand, and finally heating the sand to remove the water. Could the separation have been done in the opposite order? For example, adding the water first and extracting the insoluable residue and then heating both separately? Why or why not? I'm just starting Chem and this one has me stumped. Thanks!

Answer 1

You could add the water first. The NH4Cl and NaCl will both dissolve, leaving the sand in suspension.

You could filter off the sand.

To seperate the NH4Cl and NaCl, you could cool the water and use the difference in solubilities to seperate the two salts.