Electrolysis is a separation technique that is used to separate ions from one another. As ions can only move when liquid or in solution, for electrolysis to take place, the compound being separated must be in either of these forms. Only compounds with ionic bonding can be separated like this.

How it works[edit | edit source]

There are two charged carbon electrodes - the cathode (the negative electrode) and the anode (the positively charged one). These are placed in the liquid or solution, and the different ions move to the electrode they are attracted to. Metal ions (positively charged) are attracted to the cathode, while the non-metal ions (negatively charged) are attracted to the anode. For example, in CuO, the copper would move to the cathode and the oxygen to the anode. At these electrodes, they either gain or lose electrons to make them elements on uncharged compounds.

Half equations[edit | edit source]

Half equations show the reactions that happen at each electrode. Here are the half equations for the electrolysis of copper chloride as an example:

  • Cu2+ + 2e- --> Cu
  • 2Cl- --> Cl2 + 2e-
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