A solution of hydrochloric acid of unknown concentration was titrated with 0.12 M NaOH. If a 250-mL sample of the HCl solution required exactly 24 mL of the NaOH solution to reach the equivalence point, what was the pH of the HCl solution?
A) 12.06
B) 1.98
C) 0.12
D) 1.94
E) -0.10

Question

Quizplus · Accepted Answer

To find the pH, first calculate the concentration of HCl. The moles of NaOH used are 0.12 M * 0.024 L = 0.00288 mol. Since the reaction is 1:1, the moles of HCl are also 0.00288 mol. The concentration of HCl is 0.00288 mol / 0.250 L = 0.01152 M. The pH is -log(0.01152) = 1.94.

A Solution of Hydrochloric Acid of Unknown Concentration Was Titrated