$\ce{K2CO3}$ doesn't boil. It thermally decomposes at $\pu{1200 ^\circ C}$. However, I find conflicting information online about this. Roughly what I have found say three inconsistent things:
- It doesn't decompose
- At $\pu{1200 ^\circ C}$, it decomposes into $\ce{K + O + CO}$ (Chemiday)
- At $\pu{1200 ^\circ C}$ it decomposes into $\ce{K2O + CO2}$ (allreaction)
What actually happens when $\ce{K2CO3}$ thermally decomposes? Most sources agree with (3). But how can that be? Wouldn't it just decompose some more? $\ce{K2O}$ decomposes at $\pu{300 ^\circ C}$ into ($\ce{K2O2 + K}$) and $\ce{K2O2}$ decomposes back into ($\ce{K2O + O2}$) at $\pu{500 ^\circ C}$.
What is going on here? Is $\ce{K2O2}$ really decomposing back again to $\ce{K2O}$? If so, then at $\pu{500 ^\circ C}$ do both of these decompositions occur, cyclically pumping out $\ce{O2}$ and $\ce{K}$?
I read elsewhere that at temperatures over $\pu{500 ^\circ C}$, $\ce{K2O2}$ decomposes into ($\ce{2K + O2}$). This would resolve the conflict. But I find the source is unreliable. What is right?