The molar mass of iron(III) chloride hexahydrate, then, is equal to the molar mass of FeCl 3 plus six times the molar mass of water. In the procedure for synthesizing Fe(C 5H7O2)3 –tris(2,4pentanedionato)iron(III)– two solvents, water and methanol, will be used instead of one. This is because two of the reactants, iron(III)