1. Acids, Bases, Buffers,
Electrolytes, and pH
•
This chapter has very big
applications with biological
systems and the environment.
•
We have had a good
introduction to this with the
acid-base titration that we did
during the solutions chapter.
Damage from Acid Rain

2. A Quick Quiz...
• Name the following:
• HCl, HI, H SO , HNO , H PO
2 4 3 3 4
• Write formulas for the following
• Hydrobromic acid, Acetic acid,
Carbonic acid, Sulfuric acid,
Hypochlorous acid

3. How Did You Do?
• Hydrochloric acid, Hydroiodic acid,
Sulfuric acid, Nitric acid, Phosphoric acid
• HBr, HC H O , H CO , H SO , HClO
2 3 2 2 3 2 4

4. Definitions of Acids and Bases
1. Arrhenius acid- dissociates to produce H3O+ (H+)
when dissolved in water.
2. Arrhenius base- produces OH- when dissolved in
water
3. Bronsted-Lowry Acid- anything that donates a
proton
4. Bronsted-Lowry Base- anything that accepts a
proton
HCl
+
NH3
NH4Cl
Proton
Proton Svante Arrhenius
Donor
Acceptor

5. Dissociation- the extent to which
protons are produced or accepted
Acid
Strength
HCl
1
H2SO4
2
H3PO4
3
While H3PO4 has two more hydrogens than HCl, it does not
dissociate to the same extent.
Strong
Weak
Acids: HCl, H2SO4, HNO3
Acids: H3PO4, HC2H3O2, H2CO3
Bases: NaOH, KOH, Ba(OH)2
Bases: NH4OH, Mg(OH)2

6. Another Quick Quiz...
• Which pH value is acidic?
• pH 7.0; 5.0; or 8.0
• Why is HCl a stronger acid than H PO ?
3 4

7. How did you do?
• pH 5.0!
• HCl dissociates more than H PO
3 4

8. The pH scale: Pouvoir
Hydrogen (Power of
Hydrogen)
Acid 1----------------------------------7------------------------------------14 Base
-log of the hydrogen ion concentration (Molarity)
Calculations:
pH 2.56 = 10-2.56
(2nd function;10x;change sign;2.5)
= 2.75 x 10-3 M [H+]

9. Buffers: made from a weak acid and a
salt containing the acid’s conjugate
base.
Carbonate-Bicarbonate Buffer in Humans
An application of
Le Chatelier’s
Principle
HC2H3O2 + NaC2H3O2 <->
H+ + C2H3O2- + Na+ + C2H3O2-
Stress
Result
Add NaOH
Shift right: forms water, dissociates HC2H3O2
Add HCl
Shift left: forms HC2H3O2, undissociated

10. Hydrolysis
Hydrolysis of salts and pH:
Salt
Made From
pH
NH4NO3
weak base/strong acid
4-5
KCl
strong base/strong acid
7
NaC2H3O2
strong base/weak acid
9-10
MgCO3
weak base/weak acid
7