2. Influence of the addition of acid or base on the pH of the buffer solution - For a test portion of 50.00mL of buffer solution, calculate the equivalent volumes, i.e. the volume of acid strong (of strong base) to 0.50molL necessary for the titration of the weak base acetate A (of the weak acid "pH for each equivalence. - Pour the 0.50molL aqueous solution of HCl into the burette up to the 15mL graduation. Collect 50.00mL. buffer solution; add the HCl solution, 0.5mL per 0.5 mL, until the expected equivalence is exceeded by about 1.5mL. Record the pH value after each addition. - Pour the 0.50molL ' aqueous solution of NaOH into the burette up to the 15mL graduation. Take another 50.0mL of buffer solution; add the NaOH solution, 0.5mL per 0.5mL, until the expected equivalence is exceeded by about 1.5mL. Record the pH value after each addition. - On the same graph, orienting the abscissa axis to the left for VHC and to the right for VNOH, plot pH=f (added volume). Comment on the plot obtained. Compare the experimental pH values at equivalence with the expected values. Estimate between which pH limits the buffer zone is located, to be displayed on the graph