Rock salt is a mixture of salt (sodium chloride) and sand. Describe how you would separate rock salt to obtain salt crystals and pure dry sand.
Rock salt should be chopped into powder with further addition of a big amount of water. Salt (sodium chloride) will be dissolved and sand will remain as a precipitate. The precipitate will be filtered with further washing with water and drying to give pure dry sand. The water solution of salt should be filtered once again with further evaporation of the water and obtaining salt crystals.