Error:
MnO4%3A- %2B H2O2 %2B H3O%3A%2B %3D O2 %2B Mn%3A2%2B %2B H2O
^Unexpected character ('%')MnO4%3A- %2B H2O2 %2B H3O%3A%2B %3D O2 %2B Mn%3A2%2B %2B H2O
^Unexpected character ('%')