58. Solving a chemistry problem

72. What factors can lead to a violation of the linear dependence of optical density on concentration? At what values of D and T is the minimum measurement error provided?
To a 25 ml aliquot of a solution containing 4.5 μg/ml Fe3 was added an excess of KSCN and diluted to a final volume of 50 ml. What is the optical density of the resulting solution, measured at 570 nm in a cuvette with l=2cm. The molar absorption coefficient of the Fe thiocyanate complex is 5.5 I03.