1. Titration Unit 12: Acids and Bases Section 4: Titration

2. Titration • Titration: The controlled addition and measurement of the amount of a solution of known concentration required to react completely with a measured amount of a solution of unknown concentration • - It provides a means to determine the concentration of an unknown solution.

3. Titration • End Point: Point in a titration at which an indicator changes color

4. Equivalence Point: Point where the two solutions used in a titration are present in chemically equivalent amounts

5. Titration Sample Problem In a titration 27.4 mL of 0.0154 M Ba(OH)2 is added to a 20.0 mL sample of HCl solution of unknown concentration until the equivalence point is reached. What is the molarity of the acid solution? Ba(OH)2 + HCl  BaCl2 + H2O

6. Titration Step One – Balancing Ba(OH)2 + 2HCl BaCl2 + 2 H2O Step Two – Given and Unknown G: 27.4 mL of 0.0154 M Ba(OH)2 20.0 mL of HCl U: # M of HCl

7. Titration Step Three – Convert M to Mole 1L 1000 mL 0.0154 mol Ba(OH)2 1 L 27.4 mL 4.22 x 10-4 mol Ba(OH)2

8. Titration Step Four – Convert Ba(OH)2 to mol HCl 2 mol HCL 1 mol Ba(OH)2 4.22 x 10-4 mol Ba(OH)2 8.44 x 10-4 mol HCl

9. Titration Step Five – Use the mL of HCl to find concentration of HCl 8.44 x 10-4 mol HCl 20.0 mLHCl 1000 mL 1 L 4.22 x 10-2 m HCl

10. Titration Sample Problem # 2 In a titration 20.0 mL of 5.0 x 10-3 M NaOH is added to a 10.0 mL sample of HCl until equivalence point is reached. What is the molarity of the acid solution? NaOH + HCL  NaCl + H2O