Sunday, 28 April 2013

1.54 describe experiments to investigate electrolysis, using inert electrodes, of aqueous solutions such as sodium chloride, copper(II) sulfate and dilute sulfuric acid and predict the products

Place inert electrodes (ones that wont react) into an aqueous solution.

At the positive electrode the negatively charged ion from the compound will form an atom. At the negative electrode the atom of the positive ion will form.

sodium chloride: Hydrogen at the negative; chlorine at the positive
copper(II) sulfate: copper at the negative; oxygen at the positive
dilute sulfuric acid: Hydrogen at the negative; oxygen at the positive

If the metal in the solution is more reactive then hydrogen, the hydrogen from the water will be a product, as the metal will bond with the oxygen.

Test the products using known methods: eg damp blue litmus paper turned red by chlorine.


  1. *chlorine turns litmus paper white

  2. Yeah your right, it goes red, then it bleaches it white :)

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  4. in the electrolysis of copper sulfate i think oxygen forms at the anode and copper at the cathode, i think the sulphate ions just stay in solution

    (source: bbc bitesize and CGPwned IGCSE Chemistry revision guide)

  5. *Sodium forms on the cathode in sodium chloride

  6. yea darcy in the electrolysis of CuSO4 the sulphate ions stay in the soln. and mix with the hydrogen also left in the soln. to form H2SO4 (sulfuric acid)

  7. "At the positive electrode the atom of the positive ion will form."

    i think it is a typo- but the atom of the NEGATIVE ion will form.