Question

For the UV-Vis absorption data below, calculate the concentration for the metals M²⁺ and N²⁺ in a river sample if the unknown solution was prepared by diluting 10.00 mL of river water with 10.00 mL of ligand solution and diluted to a final volume of 100.00 mL. Assume the absorbance was measured in a 1.00-cm cell.

Solution	Wavelength	Concentration	Absorbance
M2+ standard	650 nm	1.82E-05	0.723
N2+ standard	650 nm	1.82E-05	0.312
M2+ standard	425 nm	1.82E-05	0.199
N2+ standard	425 nm	1.82E-05	0.811
Unknown	650 nm	?	0.753
Unknown	425 nm	?	0.536