Greek Claws and Entropy

Yesterdays post focused on chelating agents. These are spieceies that can form more than one dative co-ordinate bond with transition metal ions. I ended writing that chelation forms very stable complex ions but why does chelation form stable complexes? Well, the answer is quite deep routed in entropy. Essentially, the reactions produce a very large change in entropy. The enthalpy change is negligible which means that the Gibbs free energy becomes very negative (and very feasible or very spontaneous). This is quite hard ...

Greek claws

In Monday's posting I mentioned that lead could be removed from the body by using a chelating agent. But what is a chelating agent? This is not part of the IB course but is an interesting phenomena. Building on existing knowledge from topic 13.2 (Periodicity --> 'd' block / transition metal elements) you will know about ligands and complex ions. The ligands we study (eg, H2O, NH3, Cl- ) are referred to as unidentate ligands - they only form one dative covalent ...