Acid-Base Equilibria pH and pOH Relationship of Conjugate Pair acid-base strength. When acids or bases control pH: determine K predict pH When pH controls acid/base state: predict acid/base state use acid/base state to determine pH Buffer action pH titration curves

Acid-Base Equilibria pH and pOH Relationship of Conjugate Pair acid-base strength. When acids or bases control pH: determine K predict pH When pH controls acid/base state: predict acid/base state use acid/base state to determine pH Buffer action pH titration curves

pH/pOH Calculations [H3O+][OH-] = 1.0 x 10-14 pH = -log[H3O+] pOH = -log[OH-] [H3O+] = 10-pH [OH-] = 10-pH pH + pOH = 14.00 What is the pH of a solution with [H3O+] = 4.6 x 10-5 What is the pOH of a solution with [OH-] = 3.3 x 10-4 What is the pOH of a solution with [H3O+] = 2.4 x 10-3 What is [H3O+] when pH = 4.2

Strong acids and bases For strong acid solutions, [H3O+] = [acid] (except for H2SO4) For strong bases LiOH, NaOH, KOH, RbOH, [OH-] = [base] For strong bases Ca(OH)2, Ba(OH)2, etc., [OH-] = 2 x [base]

What is the pH when [H3O+] = 0.045 M? 13.995 -1.35 1.35

What is the pH when [OH-] = 6.5 x 10-4 M? 3.18 -3.18 10.81 15.18

What is the [H3O+] when pH = 3.66 M? 2.18 x 10-4 10.34 4570 3.66

What is the [OH-] when pH = 5.84 M? 1.45 x 108 3.31 x 10-6 6.92 x 10-9 5.84

A bit more on the pH scale

Acid-Base Equilibria Bronsted Acid: H+ (proton) donor Bronsted Base: H+ acceptor Acid-Base reactions: H+ transfer reaction Conjugate Acid-Base Pairs: acid conjugate base HF F- NH4+ NH3

What is the conjugage base of HNO2?

What is the conjugage acid of HPO42-?

Acid-Base Strength: Depends on Equilibrium Constant

Trends in relative acid/base strength for conjugate pairs.

Determining the Ka Value 0.10 M oxalic acid pH =

Enter question text... 5 10 50 100 200

Determining the Ka Value What is the value of Ka for an acid, HA, for which a 0.240 M solution has a pH of 3.28?

Determining Kb: A 0.300 M solution of a weak base has a pH of 9.20. What is Kb?

What is the pH of a 0.150 M solution of HCl? Predicting pH: Strong Acid solution What is the pH of a 0.150 M solution of HCl?

Using pH to determine [acid]

What is the pH of a 0.150 M solution of HF? Predicting pH: Weak Acid solution What is the pH of a 0.150 M solution of HF?

What is the pH of a 0.150 M solution of HCN? Predicting pH: Very Acid solution What is the pH of a 0.150 M solution of HCN?

Predicting pH: Strong Base solution What is the pH of a 0.150 M solution of Ca(OH)2?

Predicting pH: Weak base solution What is the pH of a 0.150 M solution of NH3?

Polyprotic Acids H2CO3 HCO3- CO32- H3PO4 H2PO4 - HPO4 2- PO4 3-