[Cu(NH3)4]2+ solutions exhibit a deep blue-violet color. How can you use spectrophotometry to confirm that this reaction has occurred and that the product formed is in fact tetraaminecopper(II) sulfate? Would you expect the wavelength
of maximun absorbance (λmax) for Cu(NH3)4 2+ to be greater than or less than λmax for Cu(H2O)6 2+? Explain.