In one trial of an investigation 50.0 mL of HCl(aq) of an unknown concentration is Tiresias with 0.10M NaOH (aq). During the titration the total volume of NaOH (aq) added and corresponding pH value of the reaction mixture are measured and recorded in the table below: 10mL-1.6pH 20.0mL-2.2pH 24.0mL-2.9pH 24.9mL-3.9pH 25.1mL-10.1pH 26.0mL-11.1pH 30.0mL-11.8pH.

Determine the total volume of NaOH(aq) added when the reaction mixture has a pH value of 7.0?
Write a balanced equation that represents this neutralization reaction?

1 answer

The large JUMP in pH is between 24.9 and 25.1 so the equivalence point must be between those two values of the volume. If you take the average pH value that will be (3.9+10.1)/2 = 7.0 so just average the volumes. That will be (24.9+25.1)/2 = ??
NaOH + HCl ==> NaCl + H20.