mass fraction of species

Ahmed

I used multiphase flow liquid liquid phase, Naphtha-water flow. Oxygen present in bulk (8ppm), chemical reaction occurred at the pipe walls acording to reaction{2Fe + 1.5 O2 + 3 H2O --- 2Fe(OH)3 }. problems occurred occurred when using fluent: 1. when define the species and chemical reaction in fluent , message appear " the species not found,I am believe that define species not correct 2. how determined the mass fraction for species for the above materials? 3. in fluent , species panel contain selected species, selected site species and selected solid species, how applied this items on the above reactions. 3. how defineing the species in the mixture. anyone help me.