Controlled Synthesis of Two Copper Oxalate Hydrate Complexes: Kinetic versus Thermodynamic Factors. A Laboratory Experiment for Undergraduates

Two compounds, K2[Cu(C2O4)2]·4H2O, 1, and K2[Cu(C2O4)2]·2H2O, 2, were synthesized under controlled conditions. By controlling the concentration of the reaction solutions, it is possible to isolate a kinetic product 1 and a thermodynamic product 2. Of interest is that the tetrahydrate compound can be converted to the dihydrate analogue by partial dehydration either in the solid state or in solution. This illustrates the fact that reactions can proceed via two routes, which can be a difficult concept for students to understand.