70. Solving a chemistry problem

4. A weighed portion of the drug Phenol was placed in a 25 ml flask and made up to the mark with a titration solution. Then 5 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. 5.73 ml of Na2S2O3 was used for titration. Write a diagram of the quantification process, indicate the indicator, fix the equivalence point. Calculate the titer and weight of the drug sample taken for analysis if the content of the active substance was 96.5%. (The molecular weight of the analyte is 94.11). 30 ml of titrant was used for the control experiment.