Error:
Cu2S %2B HNO3 %3D CuSO4 %2B Cu%28NO3%292 %2B NO %2B H2O
^Unexpected character ('%')Cu2S %2B HNO3 %3D CuSO4 %2B Cu%28NO3%292 %2B NO %2B H2O
^Unexpected character ('%')