1. ACIDS AND BASES

2. OUTCOME QUESTION(S):
C ACID/BASE AND pH
Outline acid/base theories and write acid/base equations. Include: Arrhenius, Bronsted-Lowry, Lewis.
Distinguish between strong and weak acids and bases. Include: electrolytes and non-electrolytes
Formulate an operational definition of pH and solve problems.
Vocabulary & Concepts 
Hydroxide Hydronium
Amphoteric Conjugate pairs

3. Don’t eat stuff in the lab, please
ACIDS
Taste sour
Burn when touching skin
Turn blue litmus red
Neutralize basic solutions
Corrosive to metals
Strong or weak electrolytes
You should already be aware of most of these properties…except the taste
Don’t eat stuff in the lab, please
BASES
Taste bitter
Feel slippery
Turn red litmus blue
Neutralize acidic solutions
Strong or weak electrolytes

4. Dissociates to yield aqueous hydrogen ions (H+) Bases
1. Arrhenius Definition
Acids
Dissociates to yield aqueous hydrogen ions (H+)
Bases
Dissociates to yield aqueous hydroxide ions (OH-)
H+ is also called a “proton” because a Hydrogen atom without its electron IS just a proton (it has no neutrons)
Svante Arrhenius
( )

5. H+ is responsible for acidic properties
HCl (aq) → H+ (aq) + Cl– (aq)
Remember:
ionic (↓) and highly polar (↑) compounds dissociate/ionize in solution
OH- is responsible for basic properties
NaOH (aq) → Na+ (aq) + OH– (aq)

6. I guess we need I new definition for acid and base, Lowry!
What about ammonia (NH3) Bronsted? It acts as a base, but doesn’t have OH-.
Lowry
2. The Bronsted-Lowry Definition
20 years later:
I guess we need I new definition for acid and base, Lowry!
Bronsted
Acids
proton (H+) donor
Base
proton (H+) acceptor

7. NH3 (g) + H2O(l) NH4+(aq) + OH-(aq) Bases are proton (H+) acceptor
Ammonia accepts a proton from water: H+
NH3 (g) + H2O(l)
NH4+(aq) + OH-(aq)
acceptor
donor
Hint: Follow the Hydrogen ion – who donated it, who accepted it

8. HCl(g) + H2O(l) H3O+(aq) H2O H+ + Cl-(aq) H3O+(aq)
Acids are proton (H+) donor
Hydrochloric acid donates a proton to water: H+
HCl(g) + H2O(l)
H3O+(aq)
H2O H+
+ Cl-(aq)
H3O+(aq)
donor
acceptor
H3O+ ion called the hydronium ion
H3O+ splits apart quickly, so H3O+ and H+ are written interchangeably

9. HCO3- + OH- CO32- + H2O HCO3- + H2O H2CO3 + OH-
Amphoteric: a substance which can act as either an acid or a base depending on the situation.
If you noticed…we just saw that water is amphoteric
Bicarbonate ion is also amphoteric H+
HCO OH-
CO H2O
donor
acceptor H+
HCO H2O
H2CO3 + OH-
acceptor
donor

10. B + H2O BH+ + OH- HA + H2O H3O+ + A-
Conjugate acid: product of base accepting a H+.
Conjugate base: product of an acid donating H+.
If the compound acts as a base in the forward reaction,
it will act as an acid in the reverse reaction (and vice versa)
conjugate pairs
B H2O
BH OH-
base
acid
Con. acid
Con. base
conjugate pairs
These are generic equations for an acid or base reaction
conjugate pairs
HA H2O
H3O A-
acid
base
Con. acid
Con. base
conjugate pairs

11. NH3 (g) + H2O(l) NH4+(aq) + OH-(aq) HCO3- + OH- CO32- + H2O
Label the conjugate pairs of the following reactions:
conjugate pairs
NH3 (g) + H2O(l)
NH4+(aq) + OH-(aq)
base
acid
Con. acid
Con. base
conjugate pairs
conjugate pairs
HCO OH-
CO H2O
acid
base
Con. base
Con. acid
conjugate pairs

12. Water’s electrons are attracted to BIG positive charge of Iron
Problem
Transition metal ions with charges of 2+ or 3+
can create an acidic solution.
Step 1: Formation of a hydrate:
Water’s electrons are attracted to BIG positive charge of Iron
This idea is just a curiosity for us and will not be extensively covered

13. Step 2: Loss of H+ making acidic solution.
Fe(H2O)63+ + H2O  H3O+ + Fe(H2O)5(OH)2+ H+ H
All electrons are attracted inwards, so Hydrogen ion has nothing to lose and leaves

14. electron acceptor ● electron donor
3. Lewis Definition
Acids Base
electron acceptor ● electron donor H+
CH3COO-(aq) + H2O(l) OH-(aq) + CH3COOH (aq)
base
acid
What about those metals?
I think we need a broader definition?
This is looking at the other “side of the coin” – bases accept H+ because they typically have electrons to donate…

15. CAN YOU / HAVE YOU?
C ACID/BASE AND pH
Outline acid/base theories and write acid/base equations. Include: Arrhenius, Bronsted-Lowry, Lewis.
Distinguish between strong and weak acids and bases. Include: electrolytes and non-electrolytes
Formulate an operational definition of pH and solve problems.
Vocabulary & Concepts 
Hydroxide Hydronium
Amphoteric Conjugate pairs