Transforming Na2H2EDTA.2H2O and FeCl3.6H2O into Na[Fe(EDTA)]·3H2O: A Balanced Equation for the Synthesis of an Iron(III) EDTA Complex

Here's how to balance the chemical equation for the synthesis of the iron(III) ethylenediaminetetraacetate complex (Na[Fe(EDTA)]·3H2O) from disodium ethylene diamine tetra acetic acid dihydrate (Na2H2EDTA.2H2O), iron(III) chloride hexahydrate (FeCl3.6H2O), sodium hydroxide (NaOH) and water (H2O). 1. Write down the unbalanced equation: FeCl3.6H2O + Na2H2EDTA.2H2O + NaOH --> Na[Fe(EDTA)]·3H2O + H2O + NaCl 2. Balance each element separately except hydrogen and oxygen: Let's start with sodium (Na): On the left, we have: 2 Na in Na2H2EDTA + 1 Na in NaOH = 3 Na On the right, we have: 1 Na in Na[Fe(EDTA)] Let's add 2 NaCl on the right to balance sodium, the equation now becomes: FeCl3.6H2O + Na2H2EDTA.2H2O + NaOH --> Na[Fe(EDTA)]·3H2O + H2O + 2 NaCl 3. Next, balance iron (Fe): On the left, we have: 1 Fe in FeCl3 On the right, we have: 1 Fe in Na[Fe(EDTA)] Iron is already balanced. 4. Balance chlorine (Cl): On the left, we have: 3 Cl in FeCl3 On the right, we have: 2 Cl in 2 NaCl Let's add another NaCl on the right to balance chlorine, the equation now becomes: FeCl3.6H2O + Na2H2EDTA.2H2O + NaOH --> Na[Fe(EDTA)]·3H2O + H2O + 3 NaCl 5. Now, balance oxygen and hydrogen using water molecule: Balance oxygen first: On the left, we have: 6 O in FeCl3.6H2O + 6 O in Na2H2EDTA.2H2O + 1 O in NaOH = 13 O On the right, we have: 7 O in Na[Fe(EDTA)]·3H2O + 1 O in H2O + 3 O in 3 NaCl = 11 O Adding 1 H2O on the right gives 12 O. Still have 1 O deficit on the right. The balanced equation is: FeCl3.6H2O + Na2H2EDTA.2H2O + 2 NaOH --> Na[Fe(EDTA)]·3H2O + 2 H2O + 3 NaCl In case of formation of solid residue due to the formation of Fe(OH)3 you can then balance the equation by adding additional NaOH. Please note that the above approach assumes that the reaction goes to completion. Simplified reactions do not account for side reactions and by-products. For a more accurate stoichiometric equation, specific reaction conditions and phase information would be needed.