Assertion: Magnesium can reduce Al2O3 at a temperature below $1350^\circ$C while above $1350^\circ$C aluminium can reduce MgO. Reason: The melting and boiling points of magnesium are lower than those of aluminium.

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KollegeApply · Accepted Answer

If Assertion is INCORRECT but Reason is CORRECT. Explanation: The assertion is correct because, according to the Ellingham diagram, at temperatures below $1350^\circ$C, magnesium can reduce Al2O3, while above $1350^\circ$C, aluminium can reduce MgO. The reason is incorrect because this behaviour depends on thermodynamic stability (ΔG° values) of oxides, not on melting or boiling points of the metals. The change in feasibility is due to the crossing of Ellingham lines for MgO and Al2O3 around $1350^\circ$C.

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