1. It contains ions: Molten NaCl is a liquid, and in this state, the ions (Na+ and Cl-) are free to move. This allows for the flow of electricity.
2. It provides a pathway for electron transfer: Electrolysis is the process of using electricity to drive a non-spontaneous chemical reaction. This requires a medium that can conduct electricity, and molten NaCl provides this pathway.
3. It has a lower decomposition potential than the electrode material: For electrolysis to occur, the voltage applied must be sufficient to overcome the decomposition potential of the electrolyte. Molten NaCl has a lower decomposition potential than the electrode materials typically used (like inert electrodes like graphite).
Here's a breakdown of the process:
* Cathode: At the negatively charged cathode, sodium ions (Na+) gain electrons and are reduced to sodium metal (Na).
* Anode: At the positively charged anode, chloride ions (Cl-) lose electrons and are oxidized to chlorine gas (Cl2).
Overall Reaction:
2NaCl(l) → 2Na(l) + Cl2(g)
In summary:
Molten sodium chloride undergoes electrolysis because it is an ionic compound that, when molten, allows for the free movement of ions and provides a pathway for electron transfer. The applied voltage is sufficient to overcome the decomposition potential, driving the reaction and producing sodium metal and chlorine gas.
