145. Solving a chemistry problem

30. A portion of sodium salicylate M (C7H5O3Na) = 160.10 g / mol weighing 0.0515 g was dissolved in glacial acetic acid and titrated photometrically with an indicator of tropeolin 00 at 540 nm on a photometer LMF-69, using 0.1000 as the titrant M HClO4 in glacial acetic acid. Calculate the mass fraction (%) of sodium salicylate in the preparation according to the results of titration:
V (HClO4), ml 0.0 1.0 1.2 1.6 2.0 2.0 2.4 2.6 2.8 3.0 3.1 3.2 3.4 3.6 4.0 4, four
A 0.020 0.040 0.040 0.050 0.070 0.110 0.150 0.230 0.440 0.680 1.040 1.070 1.070, 1.070, 1.070