141. Solving a chemistry problem

14. For turbidimetric determination of chloride ion, 20.0 ml of KCI solution (T = 1.051 mg / ml) was placed in a 100.0 ml volumetric flask in a 100.0 ml volumetric flask to construct a calibration curve. Then, AgCl suspensions were prepared in volumetric flasks with a capacity of 50.0 ml, containing V ml of this solution, brought up 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
50.0 ml and prepared a suspension of AgCI therein.
Determine the concentration (mg / L) of chloride ion in the analyzed solution, if the measured optical densities were equal:
Option 1
V1, ml 15.0
A 0.380