Is it true that under certain conditions, Mg can reduce Al2O3 and Al can reduce MgO? What are those conditions?
Below 1683K, the melting point of silicon, the Δ fGo curve for the formation of SiO2 lies above the Δ fGo curve for MgO, so, at temperature below 1683 K, Mg can reduce SiO2. On the other hand, above 1683 K, the ΔfGo curve for MgO lies above ΔfGo curve for SiO2. Hence, at a temperature above 1683 K, Si can reduce MgO to Mg.
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