145. Solving a chemistry problem

29. Calculate the molar concentration of the equivalent of perchloric acid solution in glacial acetic acid, if during photometric titration with this solution weighed diphenylguanidine M (C13H13N3) = 211.28 g / mol weighing 0.0696 g in glacial acetic acid with indicator tropeolin 00 at λ = 540 nm obtained the following results:
V (HCIO4) ml 0 1 2 2.4 2.8 3.2 3.4 3.6 3.7 3.8 4 4.2 4.4 4.8 5
A 0.07 0.07 0.08 0.09 0.1 0.13 0.17 0.33 0.67 1.07 1.07 1.07 1.07 1.07 1.07