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JAMB Chemistry 1980 Question 1

Question 1

Separation of Mixtures

In an attempt to remove sugar from a beaker containing a quantity of sand and sugar, 2 M ammonium chloride solution was accidentally added instead of water. Which of the following methods could be used to remove the ammonium chloride from the mixture?

  1. A.Fractional distillation
  2. B.Crystallization
  3. C.Filtration followed by evaporation
  4. D.Evaporation followed by sublimation
  5. E.Filtration followed by sublimation.
Show the answer and explanation

Answer: D (Evaporation followed by sublimation)

Explanation

Evaporating off the water leaves sand, sugar and ammonium chloride; gentle heating then makes the ammonium chloride sublime away, leaving the sand and sugar.