W ARM -U P 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?

W ARM -U P Write formulas for the following acids: Hydroiodic Acid Carbonic Acid Hydrosulfuric Acid Nitrous acid

P OH AND T ITRATIONS Acids and Bases, Day 3 Whitaker 17 December 2013

P OH Same as pH, but opposite. Goes from is basic 14 – 7.01 is acidic pOH = -log[OH - ] [OH-]=10 -pOH

REMEMBER!! The molarity of an acid is the Hydrogen (or Hydronium ) ion concentration! The molarity of a base is the Hydroxide ion concentration!

E XAMPLE Calculate the pOH for a solution of NaOH with a concentration of 1 x M. pOH = -log[OH - ] pOH = 4

E XAMPLE Calculate the pOH for a solution of KOH with a concentration of 0.01 M. pOH = -log[OH - ] pOH = 2

E XAMPLE What is the concentration of a basic solution that has a pOH of 13? [OH-] = 10 -pOH [OH-] = 1 x M

P H AND P OH As the concentration of [H+] or [OH-] goes up, the other must go down. pH + pOH = 14

E XAMPLE What is the pH of a solution that is found to have a pOH of 10? pH = 4

E XAMPLE What is the pH of a M solution of LiOH? pOH = 3 pH = 11

E XAMPLE What is the pOH of a M solution of HCl? pH = 4 pOH = 10

What is the pH of a solution HI with a concentration of.001 M? What is the concentration of a strong acid with a pH of 3? What is the pH of a solution of a NaOH with a concentration of 1.0 x M?

O BJECTIVES Define aspects of a titration. Calculate the molarity of a solution using titrations.

W ARM -U P 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?

W ARM - UP What’s the pH of a M solution of NaOH? What’s the molarity of HCl if the pOH is 13? If it takes 55 mL of M HCl to neutralize 122 mL of a NaOH solution, what is the concentration of the NaOH solution?

T ITRATIONS AND I NDICATORS Acids and Bases Whitaker 18 December 2013

T ITRATIONS 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.

N EUTRALIZATION R EACTION Remember that when an acid and base mix, a salt and water are always produced! Example: NaOH + HCl -> NaCl + H 2 O KOH + HI -> KI + H 2 O H 2 SO LiOH -> Li 2 SO H 2 O

V OCABULARY OF T ITRATIONS 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.

P ARTS OF THE B URETTE Acid or base and indicator Buret containing base or acid Stop-cock Flask Buret clamp

A LITTLE MORE MATH !!! In titrations we are looking for the concentration (Molarity) of an unknown solution. M 1 V 1 = M 2 V 2 Where M 1 is the molarity of the acid V 1 is the volume of the acid M 2 is the molarity of the base V 2 is the volume of the base

E XAMPLE 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?.0432 M

E XAMPLE 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?.0036 M

I NDICATORS !!! IndicatorAcidTransition ColorBase PhenolphthaleinClearLt Pink ( )Hot pink Methyl RedRedBuff ( )Yellow Methyl YellowRedOrange ( )Yellow LitmusPinkMauve ( )Blue Bromthymol BlueYellowGreen ( )Blue

R EVIEW [H 3 0] = [??] How do acids and bases taste? What is a strong acid? What does alkaline mean? What is the “most basic” pH?? Under what conditions do gases best dissolve?

D IFFERENT T YPES OF A CIDS Monoprotic Contains one Hydrogen HCl Diprotic Contains two Hydrogens H 2 SO 4 Triprotic Contains 3 Hydrogens H 3 PO 4

C HANGES TO M ATH When doing titrations, you must account for di- or triprotic acids by adding a 2 or 3 to the acid side.

E XAMPLE If it takes 50 mL of 0.5 M KOH solution to completely neutralize 125 mL of sulfuric acid solution (H 2 SO 4 ), what is the concentration of the H 2 SO 4 solution?