Figure 5. Formation of manganese heptoxide (Mn2O7) by reaction between KMnO4 and sulfuric acid [11]

From

Graphene – Exciting Insights into the Synthesis and Chemistry of the Miracle Material of the 21st Century and Its Implementation in Chemistry Lessons for the First Time

Andreas Schedy, Dominik Quarthal, Marco Oetken

World Journal of Chemical Education. 2018, 6(1), 43-53 doi:10.12691/wjce-6-1-8