Electrolysis of Molten Ionic Compounds

Ionic compounds will only conduct electricity if it is an aqueous solution (dissolved in water) or molten because their ions are only free to move, carrying charge in these states - not when solid. Electrolysis always occurs with more reactive metal in the compound than carbon (in the reactivity series) becasue it cannot be seperated by reduction with carbon. In all electrolysis reactions, you break apart an electrolyte (the ionic compound) with electricity using two electrodes and the ions in the electrolyte, completing the circuit. There is a positive electrode (the anode) and negative electrode (the cathode) which attract different ions in the compound depending on the charges of the ions.

Reaction at the Anode

The positive anode attracts anions in the compound which are negative ions becasue opposite charges attract. These would be negative non-metal ions becaue they gain electrons in ionic bonding (from the transfer of electrons to form a full outer shell). These then lose electrons to form their element again. Therefore, this reaction, at the anode, is oxidation.

Oxidation is loss of electrons but gain of oxygen.


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