Full Lab Manual
Introduction & Goals
Chemistry & Background
In Your Write-up
This week, you will investigate the ligand exchange reaction between NO2– and Co(NH3)5(H2O)3+. You will monitor the two steps of the reaction and determine the reaction rate constants and the order of both steps with respect to Co(NH3)5(H2O)3+.
The reaction mechanism for the substitution of a nitrite ion, NO2–, for the water ligand of Co(NH3)5(H2O)3+ is more complicated than it first appears. The reaction occurs in two steps: an initial ligand attachment followed by an isomerization to a final product. The isomer formed initially is considered to be kinetically favored, since it can form quickly. The isomer that is the final product is the thermodynamically favored isomer, since it is energetically more stable, although it is not formed initially for kinetic reasons.
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