140. Solving a chemistry problem

IV. In the turbidimetric determination of chloride ion, 20.0 ml of KCl solution (TKCl = 1.051 g / ml) was placed in a 100 ml volumetric flask in order to construct a calibration graph. 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 - Table 14.
Table 14

V, ml 2.0 4.0 6.0 8.0
A 0.22 0.47 0.70 0.94

Sample VA (ml) of the analyzed solution was diluted to 100.0 ml, then 5.00 ml of this solution was transferred to a flask with a capacity of 50.0 ml and a suspension of AgCl was prepared in it.
Determine the concentration of chloride ion in the analyzed solution, if the measured optical densities were equal - Table 15 (in accordance with the task number).
Table 15

VA task number, ml A
58 15.0 0.38