Please explain the reaction between Potassium carbonate and Magnesium

[lioric]

TL;DR Summary

Why does Mg reduce K2CO3 even though K is higher in the reactivity series

I saw this video on YouTube, ()
which shows a person making potassium with the following reaction

K2CO3 + Mg = K + C + MgO

I just don’t understand how Mg can displace K

I googled the reaction but couldn’t find much info on this reaction. Could someone give the name to this, or explain the chemistry behind it? There is a part where he uses KMnO4 and glycerin to start the reaction.

Thank you for your time.

 

[Borek]

Haven't watched the whole video, but by the sound of it it is in a way similar to reducing oxides like it is commonly done in thermites.

Reactivity series is just part of the picture, and even not the most important one. What really matters when predicting reaction products is thermodynamics: ΔG = ΔH - TΔS (and sometimes kinetics, but that's not the case here). In this particular case reaction is probably driven by the MgO creation, such oxides are very stable and have very high enthalpy of formation (more or less making them produces a lot of heat).

 

[lioric]

Haven't watched the whole video, but by the sound of it it is in a way similar to reducing oxides like it is commonly done in thermites.

Reactivity series is just part of the picture, and even not the most important one. What really matters when predicting reaction products is thermodynamics: ΔG = ΔH - TΔS (and sometimes kinetics, but that's not the case here). In this particular case reaction is probably driven by the MgO creation, such oxides are very stable and have very high enthalpy of formation (more or less making them produces a lot of heat).

Like always sir, you give a great explanation. Cannot count how many times you’ve helped out. Thank you so much. This was great.