# Decomposition of potassium permanganate under prolonged heating

When we heat potassium permanganate, the equation of the decomposition of it is: $$\ce{2KMnO4 ->[\Delta] K2MnO4 + MnO2 + O2}$$

So what will happen to potassium manganate ($\ce{K2MnO4}$) when we continue heating?

• There are numerous mixed oxide of Mn, so I believe structures like $\ce{KMnO2}$ will be formed. – permeakra Mar 10 '14 at 14:27

$\ce{2 MnO2 + 4 KOH + O2 → 2 K2MnO4 + 2 H2O}$
$$\ce{3K2MnO4 ->[\Delta] 2K3MnO4 + MnO2 + O2}$$