Answer to Question #107287 in General Chemistry for christina

Question

Calculate the pH in the titration of 10.00mL of 1.0M HCl with 1.0M NaOH after the addition of 0.0mL NaOH?

Answer 1

You're titrating hydrochloric acid, HCl, a strong acid, with sodium hydroxide, NaOH, a strong base, so right from the start you should know that the pH at equivalence point must be equal to 7.

Hydrochloric acid and sodium hydroxide react in a 1:1 mole ratio to form water and aqueous sodium chloride

HCl + NaOH → NaCl + H2O

The net ionic equation for this reaction looks like this 

H3O+(aq] + OH−(aq] = 2H2O(l]

Before NaOH is added, hydrochloric acid dissociates completely in aqueous solution to form hydronium cations and chloride anions. More specifically, you have

[H3O+]=[HCl]=1 M

This means that the pH of the solution before any strong base is added will be equal to

pH = -log(1) = 0