86. Solving a chemistry problem

31. A sample of the drug sodium salicylate was placed in a 50 ml flask, and brought to the mark with a titration solution. Then 15 ml of the resulting solution was transferred into a 50 ml volumetric flask, brought to the mark with a titration solution and titrated with 0.1 M Na2S2O3. Calculate how many ml of Na2S2O3 was spent on titration if the content of the analyte in the sample turned out to be 100%. Write a diagram of the quantification process, indicate the indicator, fix the equivalence point. (The molecular weight of the analyte is 160.11). 30 ml of titrant was used for the control experiment.