1.57C: Know that Anion and Cation are Terms Used to Refer to Negative and Positive Ions Respectively

*ANION: Negative ions (Non-Metals) that are attracted to the positive electrode

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REACTION AT THE POSITIVE ELECTRODE (ANODE)

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• Anions (Negative Non-Metal ions) are attracted to the positive electrode
• When they get to the electrode, they lose Electrons to form atoms

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Example: When Lead (II) Bromide is electrolysed, Bromide ion loses an electron to form Bromine atoms:

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2Br -     -     2e-     →     Br2

*Bromine is Formed at the Positive Electrode

*CATION: Positive ions (Metals) that are attracted to the negative electrode

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REACTION AT THE NEGATIVE ELECTRODE (CATHODE)

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• Cations (Positive Metal ions) are attracted to the negative electrode
• When they get to the electrode, they gain electrons to form Atoms

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Example: When Lead (II) Bromide is electrolysed, Lead (II) Ions gain electrons to form Lead atoms:

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Pb2+     +     2e-     →     Pb

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*Lead is Formed at the Negative Electrode