Error:
H3O%3A%2B %2B SO3%3A2- %2B Cr2O7%3A2- %3D Cr%3A3%2B %2B SO4%3A2- %2B H2O
^
Unexpected character ('%')H3O%3A%2B %2B SO3%3A2- %2B Cr2O7%3A2- %3D Cr%3A3%2B %2B SO4%3A2- %2B H2O
^
Unexpected character ('%')