0
$\begingroup$

Is it true that under certain conditions, Mg can reduce $\ce{SiO2}$ and the latter the former? What are those conditions?

$\endgroup$
2
3
$\begingroup$

Yes it is true.

Conditions are temperature in the 650 to 850 degrees C range.

There is a cool looking youtube video of the reaction, not that that makes it true.

For a more serious discussion see Production and Purification of Silicon by Magnesiothermic Reduction of Silica Fume

and Ordered Mesoporous Silicon through Magnesium Reduction of Polymer Templated Silica Thin Films

$\endgroup$
0
1
$\begingroup$

Yes, it is true below $\pu{1683 K}$, the melting point of silicon, the $\Delta_\mathrm{f}G^\circ$ curve for the formation of $\ce{SiO2}$ lies above the $\Delta_\mathrm{f}G^\circ$ curve for $\ce{MgO}$, so, at temperature below $\pu{1683 K}$, $\ce{Mg}$ can reduce $\ce{SiO2}$ to $\ce{Si}$.

On other hand, above $\pu{1683 K}$ the $\Delta_\mathrm{r}G^\circ$ curve for $\ce{MgO}$ lies above for $\ce{SiO2}$, hence at temperatures above $\pu{1683 K}$, $\ce{Si}$ can reduce $\ce{MgO}$ to $\ce{Mg}.$

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.