Themes > Science > Chemistry > Inorganic Chemistry > Acids and Bases > Acids and Bases Index > Weak acid-strong base titration The titration of a weak acid with a strong base is very similar in form to that of the titration of a strong acid with a weak base. The reaction that occurs in the solution is HA(aq) + OH-(aq) -> A-(aq) + H2O(l)When doing this kind of titration, the solution starts out acidic with a pH equal to that of the weak acid solution. As base is added, a buffer solution forms and the pH does not change rapidly until all of the weak acid reacts with the base. When it does, the equivalence point is in the base range. Working problems of this type is very similar to those of adding acid or base to a buffer. You need to first do the stoichiometry, then work an equilibrium calculation to figure out the final pH if the solution is still in the buffer range, otherwise figure out the pH from the excess acid. Examples: You titrate 100 ml of 1.00 M HCN with 1.00M NaOH. What is the pH after you add 0 ml, 50 ml, 100 ml and 150 ml of base? The Ka of HCN is 5.8*10-10. Solutions Information provided by: http://learn.chem.vt.edu