Titration Acids & Bases

Acid Dissociation Constant (Ka) The ratio of the concentration of the dissociated form of an acid to the concentration of the undissociated form. H2CO3(aq) + H2O(l)  H3O+ + HCO3- Larger Ka, the stronger the acid.

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

ACID + BASE  SALT + WATER Neutralization ACID + BASE  SALT + WATER HCl + NaOH  NaCl + H2O strong strong neutral HC2H3O2 + NaOH  NaC2H3O2 + H2O weak strong basic Salts can be neutral, acidic, or basic. Neutralization does not mean pH = 7.

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

Titration dramatic change in pH Equivalence point (endpoint) Point at which equal amounts of H3O+ and OH- have been added. Determined by… indicator color change dramatic change in pH

moles H3O+ = moles OH- MV n = MV n Titration M: Molarity V: volume n: # of H+ ions in the acid or OH- ions in the base

Titration H3O+ M = ? V = 50.0 mL n = 2 OH- M = 1.3M V = 42.5 mL n = 1 42.5 mL of 1.3M KOH are required to neutralize 50.0 mL of H2SO4. Find the molarity of H2SO4. 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 H2SO4

Buffer A solution of a weak acid and a weak base that resists large pH changes when acid or base is added. Buffer capacity: amount of acid or base that can be added without changing the pH Buffered Aspirin Bufferin