1 The chelate CuA, exhibits maximum absorption at 480 nm. When the chelating reagent is present in at least a tenfold excess, the absorbance depends only on the analytical concentration of Cu(II) and...

Extracted text: 1 The chelate CuA, exhibits maximum absorption at 480 nm. When the chelating reagent is present in at least a tenfold excess, the absorbance depends only on the analytical concentration of Cu(II) and conforms to Beer's law over a wide range. A solution in which the analytical concentration of Cu* is 2.15 × 10-*M and that for A- is 9.00 x 10- M has an absorbance of 0.759 when measured in a 1.00-cm cell at 480 nm. A solution in which the analytical concentrations of Cu** and A are 2.15 x 10-*Mand 4.00 x 10-* M, respectively, has an absorbance of 0.654 when measured under the same conditions. Use this information to calculate the formation constant K, for the process Cu+ + 2A- = CuA-