At temperatures above 100° C iron (III) oxidizes coordinated EDTA to ethylenediaminetriacetic acid in aqueous solution in the absence of molecular oxygen. The reaction proceeds with an activation energy of 28.6 kcal/mol, and its rate is directly proportional to the concentration of Fe (III) and inversely proportional to pH. At 125° C, the halflife of Fe (III) in the presence of excess EDTA is about 3 h at pH 9.3, but increases to> ...
