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Starter. Draw [Cu(EDTA)] 2- Draw the two optical isomers of [Co(H 2 O) 2 (NH 2 CH 2 CH 2 NH 2 ) 2 ] 2+. edta. L.O.: Describe the process of ligand substitution. Describe examples of ligand substitution using [Cu(H 2 O) 6 ] 2+ and [Co(H 2 O) 6 ] 2+ with ammonia and chloride ions.
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Starter Draw [Cu(EDTA)]2- Draw the two optical isomers of [Co(H2O)2(NH2CH2CH2NH2)2]2+
L.O.: • Describe the process of ligand substitution. • Describe examples of ligand substitution using [Cu(H2O)6]2+ and [Co(H2O)6]2+ with ammonia and chloride ions.
Ligand substitution and equilibria Looking at the table you have just drawn, describe and explain would happen to the position of the equilibrium if: • You increased the amount of HCl you added to no. 2 • You added more water to no. 1. • If the forward reaction in no. 2 was exothermic and you heated the solution. • EXTENSION: You added EDTA to number 3.
The Haem group • The iron (II) ion forms four bonds with the haem group, one with the O2 and another with the protein part of the Hb • The coordinate bond with the O2 is a temporary bond and allows Hb to acts as a transporter molecule • However, CO can bind instead of O2 and it does so irreversibly, rendering the haem molecule it is bound to unable to carry oxygen
Equilibrium constant, Kc • For each of the three equilibriums in your table write out the expression for the equilibrium constant
Stability constant • For equilibriums involving complexes we use the term stability constant instead (Kstab) • A large Kstab means that the complex is very stable, and so suggests that the ion is very easily formed • NB: We usually do notinclude water in the stability constant because usually it is such excess that its concentration effectively remains the same throughout.
Writing the units to Kstab • Worked out in just the same way as in Kc • Work out the units for each of the Kstab expressions you have worked out