1. III. Titration (p. 493 - 503) Ch. 16 – Determining pH and Titrations

2. Neutralization  Chemical reaction between an acid and a base.  Products are a salt (ionic compound) and water.

3. ACID + BASE  SALT + WATER HCl + NaOH  NaCl + H 2 O HC 2 H 3 O 2 + NaOH  NaC 2 H 3 O 2 + H 2 O Salts can be neutral, acidic, or basic. Neutralization does not mean pH = 7. weak strong neutral basic

4. Indicators and pH Meters  Approximate pH values can be estimated using acid-base indicators. “indicators” – are compounds whose colors are sensitive to pH. Change color in acids and bases. See pg. 493

5.  “Transition Interval” – the pH range over which an indicator changes color. Pg. 495 gives transition intervals  “pH meter” – determines the pH of a solution more exact measuring voltage. Voltage changes when hydronium ion concentration changes.

6. Titration  Titration Analytical method in which a standard solution is used to determine the concentration of an unknown solution. standard solution unknown solution

7.  Equivalence point (endpoint) Point at which equal amounts of H 3 O + and OH - have been added. Determined by… indicator color change Equivalence Poont dramatic change in pH

8. Molarity and Titration moles H 3 O + = moles OH - M  V  n = M  V  n M:Molarity V:volume n:# of H + ions in the acid or OH - ions in the base

9.  42.5 mL of 1.3M KOH are required to neutralize 50.0 mL of H 2 SO 4. Find the molarity of H 2 SO 4. H3O+H3O+ M = ? V = 50.0 mL n = 2 OH - M = 1.3M V = 42.5 mL n = 1 MV# = MV# M(50.0mL)(2) =(1.3M)(42.5mL)(1) M = 0.55M H 2 SO 4

10. 4 Step Method 1. Start with the balanced equation for the neutralization reaction. 2. Determine the moles of acid (or base) from the known solution used during the titration. 3. Determine the moles of solute of the unknown solution used during the titration. 4. Determine the molarity of the unknown solution. Good Luck!!