1. Topic: Titration Do Now:

2. Acid-Base Titration A procedure used in order to determine the molarity of an acid or baseA procedure used in order to determine the molarity of an acid or base Known volume of a solution with a known concentration (standard solution) and known volume of unknown concentration M A V A = M B V B or M A V A = M B V B

3. In order to do this, we want to add just enough acid to neutralize the base or just enough base to neutralize the acid Equivalence point total # moles H +1 ions donated by acid equals total # moles H +1 accepted by base [H +1 ] = [OH -1 ]

4. Hard to see this occur (we can’t see H + or OH - ) We can use a indicator to indicate the change from acid to base (base to acid) Which indicator do you think would work best? Common indicator used for Titrations is phenolphthalein

5. End-pointEnd-point = point at which indicator changes color – if indicator chosen correctly: end-point very close to equivalence point

6. M A V A = M B V B M a = ? V a = 40.0 mL M b = 0.100 M V b = 35.0 mL 40.0 mL 35.0mL0.100M NaOH In a titration of 40.0 mL of a nitric acid solution, the end point is reached when 35.0mL of 0.100M NaOH is added Calculate the concentration of the nitric acid solution HNO 3 + NaOH  H 2 O + NaNO 3 (X) (40.0 mL) = (0.100 M )(35.0mL) X = 0.875 M HNO 3

7. Titration Problem #2 What is the concentration of a hydrochloric acid solution50.0 mL 0.250M KOH 20.0mL of the HCl solutionWhat is the concentration of a hydrochloric acid solution if 50.0 mL of a 0.250M KOH solution is needed to neutralize 20.0mL of the HCl solution of unknown concentration? KOH + HCl  H 2 O + KCl

8. (1)(X)(20.0 mL) = (0.250 M) (50.0 mL)(1) X = 0.625 M HCl

9. Titration Problem #3 What is the concentration of a sulfuric acid solution50.0mL of a 0.25 M KOH 20.0mL of the H 2 SO 4 solutionWhat is the concentration of a sulfuric acid solution if 50.0mL of a 0.25 M KOH solution is needed to neutralize 20.0mL of the H 2 SO 4 solution of unknown concentration? H 2 SO 4 + 2 KOH  2 H 2 O + K 2 SO 4 (2)(X)(20.0ml) = (0.25M)(50.0ml)(1) X = 0.3125 M H 2 SO 4 (sulfuric acid)