2 Learning ObjectivesUnderstand the neutralization reaction … strong acid and base reactionConcept of titration, end point, and equivalence point and how they relate to neutralization reactionHow to solve titration problems … how to determine unknown acid or base concentration
3 Neutralization Reaction Acid + Base Salt + WaterCalled a neutralization reactionIs a double replacement reactionRequires use of an indicator to identify neutralization pointStrong acid + Strong base = neutral solutionIf # of H+ = # of OH-
4 TitrationA titration is a reaction where a solution of known concentration (standard solution) is used to identify a solution of unknown concentration
5 Practical Examples of Titrations Determining blood glucose levels.Determination of medical proportions in a IV drip.Amount of salt and sugar in food.Level of acidity in wine and cheese.Level of acidity in fresh water samples.
6 End PointThe end point of a titration is when the solution just barely changes colorThe equivalence point is the point where the acid and base exactly react with one anotherIdeally, the end point should be the same as the equivalence point
7 Titration Calculation In a titration, 27.4 ml of a M HCl solution is added to 20.0 mL sample of NaOH solution of unknown concentration. What is the molarity of the basic solution?HCl(aq) + NaOH(aq) H2O(l) + NaCl(aq)SASBNeutralizationFirst we need to figure moles of HCl used to neutralize NaOH in reaction.L x mol/L= x 10-4 mol of HCl
8 Titration Calculation = x 10-4 mol of HClHCl(aq) + NaOH(aq) H2O(l) + NaCl(aq)= x 10-4 mol of NaOHM of NaOH = x 10-4 mol of NaOH.0200 LM of NaOH = .021 M
9 Titration EndpointHow can you tell when you have added enough NaOH?
11 Titration Calculation Shortcut Objective: to find the M of the unknown acid or base.Use a balanced chemical equation to determine the mole/mole ratio of acid to base.MaVana=MbVbnbM = molarityV = volumen = # of H3O+ ions in the acid or OH- ions in the base. (if there are no OH- ions in the base, n = 1)
12 Cool DownHow many moles of sulfuric acid are required to completely neutralize 0.50 mol of sodium hydroxide?How many moles of potassium hydroxide are needed to completely neutralize 1.56 mol of phosphoric acid?