C. Johannesson III. Titration/Neutralization 18.4 Ch. 18- Acids & Bases
A. Neutralization HCl + NaOH → NaCl + H 2 O -Chemical reaction between an acid and a base. -Neutralization reactions ALWAYS produce a salt (which is an ionic compound) and water. -Of course, it takes the right proportion of acid and base to produce a neutral salt
C. Johannesson A. Neutralization 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
C. Johannesson B. Titration Titration Analytical method in which a standard solution is used to determine the concentration of an unknown solution. standard solution unknown solution
C. Johannesson Equivalence point Point at which equal amounts of H 3 O + and OH - have been added. B. Titration
C. Johannesson Equivalence point Determined by… indicator color change –phenolpthalein turns hot pink in a base B. Titration
C. Johannesson Equivalence point Determined by… dramatic change in pH B. Titration
B. Titration and Neutralization The solution of known concentration is called the standard solution added by using a buret Continue adding until the indicator changes color called the “end point” of the titration end points are different for different indicators
B. Titration Steps 1. A measured volume of acid of known concentration is added to a flask 2. Several drops of an indicator are added 3. A base of unknown concentration is slowly added and swirled until the indicator changes color; measure the volume delivered by the buret
B. Titration Process C. Johannesson
B. 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
C. Johannesson B. Titration 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
Worksheet Complete the worksheets on titration C. Johannesson