1. Strong Acids Ch 16
4.16.1

2. Acid/Base Definitions
Arrhenius Model
Acids produce hydrogen ions (H+) in aqueous solutions
Bases produce hydroxide ions (OH-) in aqueous solutions
Bronsted-Lowry Model
Acids are proton donors
Bases are proton acceptors
Lewis Acid Model (not on AP exam)
Svante Arrhenius

3. Conjugate Pairs
Conjugate base: everything that remains of the acid molecule after the proton is lost
Conjugate acid: formed when the proton is transferred to the base
A generic example:

4. Example HF + H2O F- + H3O+ Identify: acid base conjugate base
conjugate acid

5. At equilibrium HA(aq) + H2O(l) H3O+(aq) + A-(aq)
Ka is called the acid dissociation constant
Ka =

6. Example Write the simple dissociate reaction (omitting water) for: HCl
Write the equilibrium expression for the dissociation of the acid above

7. Strong acid Completely dissociates in water (not equilibrium)
Review: What are the 7 strong acids?

8. Acid strength and Ka
The strength of an acid is defined by the equilibrium position of its dissociation reaction (its Ka!!!)
A strong acid is one where the equilibrium lies far to the right.
Ex. HCl in water
A strong acid will have a large Ka
A strong acid yields a very, very,very weak conjugate base
The reaction does not want to reverse

9. Dissociation of Strong Acids
Strong acids are assumed to dissociate completely in solution.
Large Ka or small Ka?
Reactant favored or product favored?

10. Dissociation Constants: Strong Acids
Formula
Conjugate Base Ka
 Perchloric 
 HClO4 
 ClO4- 
 Very large 
 Hydriodic 
 HI 
 I- 
 Hydrobromic 
 HBr 
 Br- 
 Hydrochloric 
 HCl 
 Cl- 
 Nitric 
 HNO3 
 NO3- 
 Sulfuric 
 H2SO4 
 HSO4- 
 Hydronium ion 
 H3O+ 
 H2O 
 1.0