Question

You are provided with a mixture containing iron filings, ammonium chloride, sand, and sodium chloride. How will you separate these substances from the mixture?

Answer 1

Different separation techniques are present depending upon the property of the substances to be separated.

By considering this separation technique we can separate the mixture of iron filings, ammonium chloride, sand and sodium chloride

• First, we can separate iron filings by magnetic separation because iron is magnetic in nature and other components in the mixture are non-magnetic.
• The mixture is taken in a china dish and a horseshoe magnet is moved through the mixture repeatedly.
• The substance which is magnetic in nature (iron filings) will stick to the magnet and be removed from the mixture leaving behind the nonmagnetic substances.
• Then ammonium chloride is present in the mixture separated by sublimation technique because ammonium chloride is a sublimable substance and the remaining components are not.
• The mixture is taken in a china dish covered with an inverted funnel, where the stem of the funnel is covered with cotton.
• When the mixture is heated the sublimable substance (ammonium chloride) undergoes a state change from solid to a gaseous state.
• On the cooler sides of the funnel, the vapours of ammonium chloride solidify and stick there, and are removed from the mixture leaving behind the non-sublimable substance.
• The remaining mixture contains sand and sodium chloride which we can take in water.
• Sand will not dissolve in water which can be separated by the filtration method.
• Salt dissolved in the water can be separated by evaporating the solvent part, i.e., by evaporation.