2 NeutralizationNeutralization is a chemical reaction between an acid and a base.The products are a salt (any ionic compound) and water.Acid + Base Salt + WaterEx. HCl + NaOH NaCl + H2O
3 Neutralization Continued… Neutralization does not necessarily mean pH = 7Salts can be neutral, acidic, or basic depending on the strength of the acid and base involved in the reaction.Ex. HCl + NaOH NaCl + H2Ostrong strong neutralEx. HC2H3O2 + NaOH NaC2H3O2 + H2Oweak strong basic
4 IndicatorsAcid-base indicators are compounds whose colors are sensitive to pH.- the color of the indicator changes as pH changes- indicators are typically made from weak acids or basesAcid-base indicators are good for determining approximate pH.If exact pH is needed, a pH meter can be used.
5 TitrationTitration is an analytical method in which a standard solution is used to determine the concentration of an unknown solution.The equivalence point tells you when equal amounts of H3O+ and OH- are in the solution.- you know you have reached the equivalence pointwhen there is a dramatic change in pH or a colorchange in the indicator.The point at which the indicator changes color is called the endpoint.
6 Calculations moles H3O+ = moles OH- M * V * n = M * V * n M = molarity (moles/L)V = volume (L)n = # of H+ ions in the acid OR# of OH- ions in the base
7 Practice42.5 mL of 1.3M KOH are required to neutralize 50.0 mL of H2SO4. Find the molarity of H2SO4.H3O+M = ?V = 50.0 mLn = 2OH-M = 1.3MV = 42.5 mLn = 1MV# = MV#M(50.0mL)(2) = (1.3M)(42.5mL)(1)M = 0.55M H2SO4