Slide 1 of 52

Ch.16. Acids and Bases (the fundamentals)

Slide 2 of 52

Contents16-1 The Arrhenius Theory: A Brief Review

16-2 Brønsted-Lowry Theory of Acids and Bases

16-3 The Self-Ionization of Water and the pH Scale

16-4 Strong Acids and Strong Bases

16-5 Weak Acids and Weak Bases

16-6 Polyprotic Acids

16-7 Ions as Acids and Bases

16-8 Molecular Structure Acid-Base Behavior

Slide 3 of 52

16-1 The Arrhenius Theory: A Brief Review

HCl(g) → H+(aq) + Cl-(aq)

NaOH(s) → Na+(aq) + OH-(aq)H2O

H2O

Na+(aq) + OH-(aq) + H+(aq) + Cl-(aq) → H2O(l) + Na+(aq) + Cl-(aq)

H+(aq) + OH-(aq) → H2O(l)

Arrhenius theory did not handle non OH- bases such as ammonia very well.

Slide 4 of 52

16-2 Brønsted-Lowry Theory of Acids and Bases

An acid is a proton donor. A base is a proton acceptor.

NH3 + H2O NH4+ + OH-

NH4+ + OH- NH3 + H2O

base acid

baseacid

conjugate acid

conjugate base

?? ??

Slide 5 of 52

The Solvated Proton

Slide 6 of 52

Base Ionization Constant

NH3 + H2O NH4+ + OH-

Kc= [NH3][H2O]

[NH4+][OH-]

Kb= Kc[H2O] = [NH3]

[NH4+][OH-]

= 1.810-5

base acidconjugate

acid

conjugate

base

Slide 7 of 52

Acid Ionization Constant

CH3CO2H + H2O CH3CO2- + H3O+

Kc= [CH3CO2H][H2O]

[CH3CO2-][H3O+]

Ka= Kc[H2O] = = 1.810-5

[CH3CO2H]

[CH3CO2-][H3O+]

baseacidconjugate

acid

conjugate

base

Slide 8 of 52

Slide 9 of 52

A Weak Base

Slide 10 of 52

A Weak Acid

Slide 11 of 52

A Strong Acid

Slide 12 of 52

Worked Examples Follow:

Slide 13 of 52

Slide 14 of 52

Slide 15 of 52

CRS Questions Follow:

Slide 16 of 52

O HNH

H

H HN H

H

O H

- -

3NH 2H OOH 2NH + +

In the reaction depicted below, which species are acids?

3 21. NH , H O 3 22. NH , NH 23. OH , NH

24. OH , H O35. NH , OH

Slide 17 of 52

O HNH

H

H HN H

H

O H

- -

3NH 2H OOH 2NH + +

In the reaction depicted below, which species are acids?

3 21. NH , H O 3 22. NH , NH 23. OH , NH

24. OH , H O35. NH , OH