Fehler:
HCl %2B Na2S2O3 %3D H2O %2B S %2B SO2 %2B NaCl
^
Unerwartets Zeichen ('%')HCl %2B Na2S2O3 %3D H2O %2B S %2B SO2 %2B NaCl
^
Unerwartets Zeichen ('%')