075. Solving a chemistry problem

3. The analyzed solution of hydrochloric acid with a volume of 25.00 ml was diluted with distilled water to 100 ml and the test solution was obtained. We carried out potentiometric titration of 20.00 ml of the test solution with a standard 0.10 mol/l sodium hydroxide solution and obtained the following results:
V, ml 18.00 19.00 19.90 20.00 20.10 21.00 22.00
pH 2.28 2.59 3.60 7.0 10.60 11.49 11.68
Determine the molar concentration of hydrochloric acid in the solution being analyzed.