Preparation of Salts

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Preparation of Salts

• By SK Chan

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Preparing sodium chloride

• Add NaOH to HCl slowly to get a neutral solution.
  (How?)
• Concentrate the solution by evaporation until
  some white crystals around the edge of solution
  are seen.
• Leave the solution to evaporate slowly at room
  temperature to get bigger crystals.
• Separate the crystals by filtration.

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How to get a neutral solution?
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Preparing salt from an acid and a base, CuSO4.5H2O

• Add black copper oxide to sulphuric acid and stir
  with a glass rod.
• Keep adding until no more will dissolve (react).
• Filter the mixture in another beaker.
• Pour the solution into an evaporating dish.
• Stop heating when some crystals are seen around
  the edge of solution.
• Leave the solution to crystallize slowly.

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Preparing salt from an acid and a base, CuSO4.5H2O
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Making insoluble salts

• Some salts are insoluble.
• They can be prepared by a precipitation reaction.

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Other methods for soluble salts

• Acid carbonate ? salt water carbon dioxide

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Other methods for soluble salts

• Acid metal ? salt hydrogen

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Salt preparation project

• Decide a salt for your group.
• Design an experiment to prepare it.
• In a piece of paper, write down the chemicals and
  apparatus required draft the experimental
  procedure and hand it to your teacher for
  comment.

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Salt preparation project

• Decide a salt for your group.
• Design an experiment to prepare it.
• In a piece of paper, write down the chemicals and
  apparatus required draft the experimental
  procedure and hand it to your teacher for
  comment.

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Salt preparation project

• After making modification (if needed) to your
  designed experiment. Carry out the preparation in
  the laboratory periods.
• Write a report on the designed experiment.

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Writing a laboratory report

• Title
• Date
• Objective(Name of the salt crystals prepared)
• Chemicals and apparatus
• Principle (Which method? Equation of reaction,
  Separation method)
• Procedure
• Result (What is the appearance of your crystals?)