This research abstract examines the chemical equilibrium of the inorganic complex potassium tris(oxalato)ferrate(III) through a series of ligand displacement reactions. The stability of the metal-ligand bonds in this complex are evaluated by applying Le Chatelier's principle - displacing the oxalato ligands causes the color of the solution to change as the equilibrium shifts. Reversing the reactions by displacing the new ligands with oxalate allows the original complex to reform, demonstrating how inorganic complexes in dynamic equilibrium can adjust to external stresses.

1. Nuria Astrid Perez Varela
Research Abstract
San Bernardino Valley College
11/16/2012
Exposing the Principles of Chemical Equilibrium: Shifting Back and For a
Potassium Tris(oxalato)ferrate(III) Solution
Proposal description
The chemical equilibrium of inorganic complexes was explored by evaluating the
interrelation between ligand coordination, displacement, and precipitation equilibrium of
Potassium Tris(oxalato)ferrate(III).
Abstract
In a qualitative analysis test, the chemical equilibrium of inorganic complexes is
explored by evaluating the interrelation between ligand coordination, displacement, and
precipitation equilibrium of Potassium Tris(oxalato)ferrate(III) (Gonzales et al). In
dynamic equilibrium, the rates of the forward and reverse reaction of a system are equal,
and no net change occurs in the concentration of the products or reactants because the
reactions have reached a balance (Silberberg).
Le Chatelier's principle states if an external stress is applied to a system of
equilibrium, the system adjusts to relieve the stress (Rickard). For inorganic complexes,
any displacement of the ligands bonded to a metal ion will result to a change of the
absorbed wavelength, modifying the color reflected by the compound. The change in
color is used to determine the stability and strength of a metal-ligand compound—the
more stable the metal-ligand bond is, the more difficult it is for another ligand to displace
it—. Furthermore, a displacement may lead to a generation of a non-soluble product
depending on the competition reactant added to the complex.
A series of competition reactions was performed to evaluate the stability of
Potassium Tris(oxalato)ferrate(III). The oxalato ligand of the inorganic complex was
displaced producing changes of the color of the solution. The new ligands were displaced
with oxalate in order to reverse the reaction and form the original complex.
The versatility of the potassium salt allows physical contemplation of the changes
that an inorganic complex in equilibrium can undergo when an external stress is applied.
Work cited
Gonzales, Gabriel, and Seco, Miguel. Potassium Tris(oxalato)ferrate(III): A Versatile
Compound To Illustrate the Principles of Chemical Equilibria. Journal of Chemical
Education.2004 81 (8), 1193. Web
T. G., Rickard, L, H., & Weiss, G. S. Modification of "Le Chartelier's Principle in Iron
Thiocyanate Equilibrium". Experiments in General Chemistry: Principles & Modern
Application (9th ed.). Upper Saddle River: Pearson Prentice Hall, 2007. Web
Silberberg, Martin S. Chemistry: The Molecular Nature of Matter and Change. Sixth ed.
McGraw-Hill, 2012. Print.