During the titration of a strong acid with a strong base, the pH calculations are based on the concentration of the residual H3O+ or OH− ions. For instance, 0.1 M HCl dissociates into 0.1 M H3O+ and Cl− ions, starting with an initial pH of approximately 1. The introduction of 0.1 M NaOH alters the H3O+ concentration in the solution. The new concentration can be calculated by subtracting the total moles of OH− from those of H3O+ and dividing by the total volume. Now, the resultant pH has risen to 1.48. The continued addition of NaOH solution neutralizes all the H3O+, raising the pH to 7 at the equivalence point. Beyond this point, OH− govern and determine the pH. Adding more NaOH solution containing 0.007 moles of OH− results in a final OH− concentration of 0.017 M with the corresponding pOH of 1.77 and pH of 12.23.