213 PHC Dr. Mona AlShehri 5th Lecture

(1) Gary D. Christian, Analytical Chemistry, 6 th edition.

 Explain the different stages of strong and weak acid-base titration curves.  Calculate the pH at these stages.

Titration curves

 An acid-base titration involves a neutralization reaction ( an acid is reacted with equivalent amount of base)  A titration curve is constructed by plotting the pH of the solution as a function of the volume of the titrant added  The titrant is always a strong acid or base  The analyte may be either a strong acid or base or a weak acid or base

Both titrant (NaOH) and analyte (HCl) are completely ionized e.g. titration of HCl with NaOH HCl + NaOH  NaCl + H 2 O

Both titrant (HCl)and analyte (NaOH)are completely ionized e.g. titration of NaOH with HCl NaOH + HCl  NaCl + H 2 O

The analyte (CH 3 COOH) is partially ionized e.g. titration of CH 3 COOH with NaOH CH 3 COOH + NaOH  CH 3 COONa + H 2 O

The analyte (NH 3 ) is partially ionized e.g. titration of NH 3 with HCl NH 3 + HCl  NH 4 Cl

 Strong and weak acid-base titration curves.  pH calculations.