Make Copper Sulphate in a Science Lab

Copper sulfate is an inorganic compound commonly found in pesticide products used to kill bacteria, algae, plants, snails, and fungi.[1] It is a combination of copper oxide and sulfuric acid. Copper sulfate is also often used to grow brilliant blue crystals as a fun science experiment.

Steps

Making a Copper Sulfate Solution

  1. Gather all of your supplies. Place the items together in one area. Having all of the equipment you need in one place will prevent you from having to stop in the middle of a task to look for a missing item.[2]
    • Copper Oxide
    • Sulphuric Acid
    • Eye Protection
    • Glass Beaker
    • Conical Flask
    • Spatula
    • Glass Stirring Rod
    • Evaporating Dish
    • Bunsen Burner
    • Tripod
    • Filter Paper
    • Filter Funnel
  2. Set up your work station. Place the glass beaker on top of the tripod over the Bunsen burner. Put on your eye protection.[2]
  3. Pour the sulfuric acid into the glass beaker. Heat the solution until it is almost boiling.[2]
  4. Add small pieces of copper oxide to the hot solution. Make sure to use the spatula to avoid burning yourself.[2]
  5. Use the glass stirring rod to stir lightly. You do not want to stir too vigorously and splash the hot solution onto your skin. Stir for up to 30 seconds after each new addition. [2]
  6. Continue to heat the solution after the last piece of copper oxide has been added. You want to ensure that the chemical reaction has occurred. This may take 1 to 2 minutes. The solution will look cloudy with a black powder.[2]
  7. Turn off the Bunsen burner. You may want to use a litmus paper to make sure no acid remains in the solution. If acid does remain, fumes will appear after the solution has been filtered.[2]
  8. Set the beaker aside. It is okay to allow the beaker to cool while you prepare for the filtration process.[2]

Filtering the Copper Sulfate Solution

  1. Insert the filter funnel into the neck of the conical flask. Fold the filter paper to fit into the funnel.[2]
    • Polythene filter funnels are cheaper and safer than glass funnels. The filter funnel diameter is should not be too big. Otherwise, the filtration set-up will be unstable.[2]
  2. Check to see the beaker is safe to hold at the top. If the beaker is too hot, wait for it to cool more. The contents will remain hot, so continue to handle with care.[2]
  3. Swirl the solution by gently moving the beaker in a circular direction. Pour the solution into the filter funnel.[2]
  4. Wait for the solution to filter. A clear blue solution should be in the flask. If it is still cloudy with black powder, repeat the filtration process until clear.[2]

Growing Copper Sulfate Crystals

  1. Rinse the beaker. You will be using the beaker to house the growing crystals. You do not want to contaminate your filtered solution.
  2. Pour the clear blue solution into the beaker. Be careful while doing so. The solution may still be hot enough to burn you.
  3. Leave the beaker in a warm place where it will not be disturbed for a week or more. As the water evaporates, you will see the crystals beginning to form.[2]
    • This evaporative crystallization method may take a few weeks depending on how warm the area where the beaker is being stored is. Well-formed crystals will grow.[3]
    • You can also heat the solution over a Bunsen burner until one half to two thirds of the water has evaporated. Allow the solution to cool. This cooling crystallization method will most likely result in irregularly shaped crystals.[3]

Warnings

Remember, copper sulfate is a harmful irritant. Do not ingest. Handle with care, and always wash your hands after touching it.

Things You'll Need

  • Copper Oxide
  • Sulphuric Acid
  • Eye Protection
  • Glass Beaker
  • Conical Flask
  • Spatula
  • Glass Stirring Rod
  • Evaporating Dish
  • Bunsen Burner
  • Tripod
  • Filter Paper
  • Filter Funnel

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Sources and Citations

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