Error:
H2O %2B Mn %2B K2S2O8 %3D H2SO4 %2B K2SO4 %2B KMnO4
^Unexpected character ('%')H2O %2B Mn %2B K2S2O8 %3D H2SO4 %2B K2SO4 %2B KMnO4
^Unexpected character ('%')