II -NH3-EDTA Competing Ligands

This expression is obtained by assuming that most of the Cu(II) will be present as the EDTA complex, CuY, approximately 0.01 M. The small amount x that does dissociate enters the Cu -NH5 system, and the Y enters the H4Y protonic system. Thus, we approach this problem by conceiving the process as placing 0.010 mol of CuY in one liter of the 0.2 M ammonia buffer and allowing it to go to equilibrium. 

This compares with calculated from the complete 

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