1. Physical Separation
a) Dissolution: Add a sufficient amount of water to dissolve the salt present in the sand-salt mixture. Sand is insoluble in water, whereas salt (NaCl) completely dissolves in it.
b) Filtration: Prepare a filtration apparatus with a funnel and a filter paper. Pour the sand-salt-water mixture into the filter paper. The sand particles will be retained on the filter paper, while the salt solution passes through and gets collected in the beaker placed underneath the funnel.
2. Chemical Separation - Precipitation
a) Evaporation: Heat the salt solution obtained from filtration until all the water evaporates, leaving behind salt crystals.
3. Recrystallization
a) If desired, the salt crystals can be further purified by recrystallization. Dissolve the obtained salt crystals in hot water and filter the solution to remove any impurities. Allow the filtered solution to cool down slowly, which will cause the dissolved salt to recrystallize.
b) Filtration: Filter the recrystallized salt crystals, wash with a small amount of cold water, and allow drying.
4. Collection of Sand
a) The sand retained on the filter paper can be collected and dried for further use.
By following this method, you can effectively separate sand and salt. The key steps involve using the differences in solubility and physical properties of sand and salt to achieve the desired separation.
