141. Solving a chemistry problem

The analyzed HCl solution was diluted in a volumetric flask to 100.0 ml and an aliquot of 20.00 ml was titrated potentiometrically with 0.1000 M NaOH. Construct titration curves in the coordinates pH - V and ΔpH / ΔV - V and determine the mass (mg) of HCl in solution from the following data:

V (NaOH), ml 1.30 1.50 1.60 1.65 1.68 1.70 1.72 1.741.80
pH 1.78 3.03 3.34 3.64 4.03 6.98 9.96 10.36 10.66