+ UNIT 10 – Acids and Bases You need a Pre-1982 Penny For Lab on Friday!!

+ Activity Prep: Computer Log-On Select a ChromeBook/Computer – working in pairs within your learning team Log on to the Computer

+ Warm Up What is the pH of a M solution of HI? What is the pOH of a M solution of NaOH? What is the [H+] concentration of a solution of HBr that has a pH of 5.6? What is the pH of a 0.56 M solution of KOH?

+ Warm Up What is the pH of a M solution of HI? 3.11 What is the pOH of a M solution of NaOH? 1.35 What is the [H+] concentration of a solution of HBr that has a pH of 5.6? 2.51 x What is the pH of a 0.56 M solution of KOH? 13.75

+ Homework Check 1) 3 2) ) ) ) ) ) ) ) 2.5 x ) 6.3x ) 3.16x ) ) ) ) ) ) ) ).55 20) ) 3.98x ) ) 2.23x ) 3.63x ) ) ) ) ) ) 12.88

+ Objectives Define aspects of a titration. Calculate the molarity of a solution using titration.

+ Titrations

+ A Few Definitions Monoprotic acid- when an acid can only donate one proton (H+). Ex. HCl Diprotic-when an acid can donate 2 protons (H+) Ex. H 2 SO 4 Triprotic-when an acid can donate 3 proton (H+) Ex. H 3 PO 4

+ Titrations A titration is a way of determining the molarity of an unknown solution by adding small volumes of a solution with a known molarity. Involve neutralization reactions. Acid + Base = Water + Salt

+ Neutralization Reaction Remember that when an acid and base mix, a salt and water are always produced! Example: NaOH + HBr -> NaBr + H 2 O KOH + HI -> ________ + __________

+ Predict The Neutralization Reaction Products & Write A Balance Equation (1) Hydrochloric Acid and Calcium Hydroxide 

+ Vocabulary of Titrations Titrant- the solution of known concentration Analyte- the solution being analyzed The equivalence point- point where exactly enough titrant has been added to react with all of the analyte. Indicator- a compound that changes color at certain pH’s.

+ Parts of the Titration Set-Up Indicator

+ The math that goes with titrations. In titrations we are looking for the concentration (Molarity) of an unknown solution. M A V A = M B V B Where M A is the molarity of the acid V A is the volume of the acid M B is the molarity of the base V B is the volume of the base

+ Example If it takes 54 mL of 0.1 M NaOH to neutralize 125 mL of an HCl solution, what is the concentration of the HCl? M A V A = M B V B

+ Example If it takes 25 mL of 0.05 M HCl to neutralize 345 mL of NaOH solution, what is the concentration of the NaOH solution? M A V A = M B V B

+ Example: g of sodium hydroxide were dissolved in mL of solution to prepare the titrant. Then mL of sulfuric acid were titrated with the titrant. It took mL of sodium hydroxide solution to titrate to the end point. What is the molarity of the sulfuric acid?

+ Example If it takes 50 mL of 0.5 M KOH solution to completely neutralize 125 mL of nitric acid solution what is the concentration of the nitric acid solution?

+ You Try 60 ml of 1.2 M NaOH are required to titrate 40 ml of HF. What is the M of the HF?

+ ACID-BASE TITRATION SIMULATION

+ Titration Lab Simulation Work in pairs within your learning team Follow Assigned Task Directions If you overshoot the titration, you must start over! Once you have reached the flash point… do the math and calculate the molarity of the unknown solution and enter it into the program. You must show Mr. Hawkins the “CORRECT” screen to receive credit for the lab. If time permits, perform another titration, using the opposite criteria on your sheet (i.e. switch acids and bases) – compare your results.

+ Titration Lab Simulation Link to Simulation: /projectfolder/flashfiles/stoichiometry/acid_base.ht ml

+ What We’ve Learned Today: How to define aspects of a titration. How to calculate the molarity of a solution using titrations.

+ HOMEWORK (1)Titration Worksheet 2-4, 7, 9, 10, 14 (2)Test Thursday – Unit 9: Solutions Unit 10: Acids & Bases You need a Pre-1982 Penny For Lab on Friday!!

+ Exit Card 50 ml of 0.3 M KOH are required to titrate 60 ml of H 2 SO 4. What is the M of the H 2 SO 4 ? 60 ml of 1.2 M NaOH are required to titrate 40 ml of HF. What is the M of the HF? What volume of 0.40 M NaOH would be required to titrate 100 ml of 0.25 M HCl?