Chemistry – Metals - Extraction of metals | e-Consult
Metals - Extraction of metals (1 questions)
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Magnesium is extracted from magnesium oxide (MgO) by electrolysis of molten MgO. The chemical equation for this process is:
| MgO(l) → Mg(l) + O₂(g) |
A reducing agent is needed because magnesium oxide is an oxide, meaning it has already combined with oxygen. To extract magnesium, we need to reverse this process and remove the oxygen. Electrolysis provides the energy to break the ionic bonds in the molten MgO, allowing the magnesium ions (Mg²⁺) to be reduced to molten magnesium (Mg) at the cathode and oxygen ions (O²⁻) to be oxidized to oxygen gas (O₂) at the anode.
The conditions required for this extraction to occur are:
- Molten State: MgO must be in a molten state. This is because ionic compounds only exist in the molten state when they are heated to a high temperature.
- Electrolysis: The process must be carried out using electrolysis, which involves passing an electric current through the molten MgO.
- Suitable Electrolyte: A suitable electrolyte is required to conduct the electric current. Molten MgO itself acts as the electrolyte.
- Controlled Temperature: The temperature must be carefully controlled to maintain the molten state of MgO and ensure efficient electrolysis.