26. Solving a chemistry problem

68c. A 50.00 ml aliquot of the analyzed solution containing copper cation Cu2 was titrated with a standard solution of complexone III (EDTA) in the presence of acetate buffer. The end of the titration was determined using the spectrophotometric titration method at a wavelength of 745 nm, at which only the reaction product, copper(II) complexonate, absorbs light.
Using the data below, construct a titration curve1 in the coordinates optical density A - volume V(EDTA) of the added titrant and calculate the molar concentration and titer (g/ml) of the copper cation Cu2 in the analyzed solution (do not take into account the dilution of the solution during the titration process).
Option c(EDTA),
mol/l Optical density of solution A
after adding EDTA
1.00 ml 1.50 ml 2.00 ml 2.50 ml 3.00 ml 3.50 ml 4.00 ml
g 0.0813 0.098 0.149 0.198 0.245 0.270 0.2275 0.275
To construct a titration curve when plotting scales on coordinate axes, it is recommended to choose for each scale a scale such that one small cell on graph paper would correspond to V(EDTA) = 0.05 ml on the abscissa axis, and A = 0.005 on the ordinate axis.