5. Solving a chemistry problem

7. In the turbidimetric determination of the chloride ion, to construct a calibration curve, 20.0 ml of a KCI solution (T = 1.051 mg/ml) was placed in a volumetric flask with a capacity of 100.0 ml. then, in volumetric flasks with a capacity of 50.0 ml containing V ml of this solution, suspensions of AgCI were prepared, brought to the mark with water, and their optical densities were measured:
V ml 2.0 4.0 6.0 8 0
A 0 220 0.470 0 700 0.940
Sample Vi ml of the analyzed solution was diluted to 100.0 ml, then 5.00 ml of this solution was transferred into a flask with a capacity of
50.0 ml and prepared a suspension of AgCI in it.
Determine the concentration (mg/l) of the chloride ion in the analyzed solution, if the measured optical densities were equal:
Option 1
V1, ml 15.0
A 0.380