ReactionBalance
ReactionBalance[rxn] returns a version of the reaction rxn in which the stoichiometric coefficients for elements in the reactants and products are balanced.
Examples
ReactionBalance["H2 + O2 -> H2O"]ReactionBalance["Fe + O2 -> Fe2O3"]ReactionBalance["C6H12O6 + O2 -> CO2 + H2O"]*See the official Wolfram Language Reference for more details.