Overall reaction:
2H₄EDTA + Fe₂(SO4)₃ + Na₂SO₄ + 4Ba(OH)₂ o 8H₂O --> 2FeNaEDTA + 4BaSO₄ + 16H₂O

Like the acid-base reaction above, this reaction requires some stoichiometry to calculate the correct amounts of reactants to use. Note that the molar mass of the EDTA acid is 292.24 g and the molar mass of the EDTA iron is 367.05 g. For example, if you need 7.9 g of EDTA iron:

You may not be able to find EDTA iron or other chelated iron in your chemistry lab, and it is pretty expensive to buy from a chemical supplier. However, there is a way to make the chelated iron in the lab if you have EDTA acid, which is somewhat easier to find.

The following process was invented by Josh Porter in the North Hunterdon High School chemistry lab. Although it seemed to work pretty well, it is still considered experimental, and the product should be tested after the reaction is complete to make sure the process worked correctly.

Tetraammonium EDTA chelating agent is an aqueous solution of the tetraammonium salt of ethylenediaminetetraacetic acid.

Active Ingredient Name	Tetraammonium ethylenediaminetetraacetate
CAS Number	22473-78-5
Chemical Formula	C10H28N6O8 or
(NH4OOCCH2)2NCH2CH2N(CH2COONH4)2
Molecular Weight	362.2
Other Names	(NH4)4 EDTA