Fe+3 solution is more acidic because it produces H+ ion in the aqueous solution, but Fe+2 is not. The following reaction represents this- [Fe(H2O)6]3+H2O ----------> [Fe(H2O)5OH]+2+ + H3O+(aq) Therefore - a) Fe+3 b) ii Solution Fe+3 solution is more acidic because it produces H+ ion in the aqueous solution, but Fe+2 is not. The following reaction represents this- [Fe(H2O)6]3+H2O ----------> [Fe(H2O)5OH]+2+ + H3O+(aq) Therefore - a) Fe+3 b) ii.