question_answer 61)

  You are provided with a mixture containing sand, iron filings, ammonium chloride and sodium chloride. Describe the procedures you would use to separate these constituents from the mixture?

Answer:

  (i) Remove iron filings with the help of magnet Place the mixture on a paper of petridish, move a bar magnet many times over the mixture. Iron filings get attached to the magnet and get separated. (ii) Remove ammonium chloride from sand and sodium chloride by sublimation The remaining mixture is transferred to China dish and subjected to sublimation. Ammonium chloride will get vaporised and change into vapours and on condensation will form  Sand and sodium chloride will be left in China dish. (iii) Remove sand from sodium chloride by filtration after dissolution Dissolve the sand and sodium chloride in water, Sodium chloride will dissolve. Filter the solution. Sand will be left as residue and is separated. (iv) Get sodium chloride by evaporation or crystallization. In the filtrate sodium chloride is present. So, evaporate the filtrate to dryness to get sodium chloride back or use crystallisation.