Observe the following Ellingham diagram, and identify the incorrect statement regarding it
Observe the following Ellingham diagram, and identify the incorrect statement regarding it
At point ' $\mathrm{A}$ ' for the reduction of $\mathrm{Al}_2 \mathrm{O}_3$ by $\mathrm{Mg}$, $\Delta \mathrm{G}^{\circ}=0$
Below $1673 \mathrm{~K}, \mathrm{Mg}$ can reduce $\mathrm{Al}_2 \mathrm{O}_3$ to $\mathrm{Al}$
Below $1673 \mathrm{~K}, \mathrm{Al}$ can reduce $\mathrm{MgO}$ to $\mathrm{Mg}$
Above $1673 \mathrm{~K}, \mathrm{Al}$ can reduce $\mathrm{MgO}$ to $\mathrm{Mg}$
Solution
Since the $\frac{4}{3} \mathrm{Al}+\mathrm{O}_2 \rightarrow \frac{2}{3} \mathrm{Al}_2 \mathrm{O}_3$ line lies above the $2 \mathrm{Mg}+\mathrm{O}_2 \rightarrow 2 \mathrm{MgO}$ line, $\mathrm{Al}$ cannot reduce $\mathrm{MgO}+\mathrm{Mg}$ below $1673 \mathrm{~K}$.
This is because of the less negative value of $\Delta \mathrm{G}^{\circ}$ for $\frac{4}{3} \mathrm{Al}+\mathrm{O}_2 \rightarrow \frac{2}{3} \mathrm{Al}_2 \mathrm{O}_3$
