Arrhenius Theory of Acids and Bases
What are Acids Wh
t
A id
and Bases?
Acids
• the properties are due to the presence of
_______________________________________
• Eg. HCl
Bases
‐ the properties are due to the presence of ______________________________________
‐ Eg. NaOH
LIMITATIONS: ((1)) H+ (aq) does not exist in water Æ
(2)
Bronsted‐Lowry
Bronsted
Lowry Theory of Acids and Bases
Theory of Acids and Bases
Lewis Acids and Bases
Acids are substances that produce a Lewis acid is a substance, such as the H+ ion, that can accept a pair of nonbonding electrons Æ
p
g
_________________________
____________________________________
A Lewis base is a substance, such as the OH‐ ion, that can donate a pair of nonbonding electrons Æ __________________
donate a pair of nonbonding electrons Æ
Eg. HCl(g) + H2O(l) → H3O+(aq) + Cl‐(aq)
Bases are substances that can accept a ____________________________________
Eg. NH3 (g) + H2O(l) ÅÆ NH4+(aq) + OH–(aq)
____________
_____________
Conjugate Acid‐Base
Conjugate Acid
Base Pairs
Pairs
Conjugate acid‐base pairs differ from each other by the presence or absence of a single hydrogen ion (proton). Every acid has a conjugate base, and every base has a conjugate acid
conjugate acid.
What are Strong Acids?
What are Strong Acids?
Strong acids produce many H+ ions (or H3O+ ions)
Eg. HCl(g) + H2O(l) → H3O+(aq) + Cl‐(aq)
Weak acids produce few H+ ions
Eg. HC2H3O2 (aq) ↔ H+(aq) + C2H3O2‐(aq)
The stronger the acid, _________________________
Polyprotic Acids ____________________________
H2SO4 (aq)
→ H+(aq) + HSO4‐(aq)
4 (aq) →
HSO4‐(aq) → H+(aq) + SO42‐(aq)
What are Strong Bases?
What are Strong Bases?
Strong bases produce many OH‐ ions
Eg. Mg(OH)2 (aq) → Mg2+(aq) + 2 OH‐(aq)
Weak bases produce few OH‐ ions
Eg.
NH2CH3(aq) + H2O(l) ↔ NH3CH3+(aq) + OH‐(aq)
The stronger the base, __________________________
Calculating Ion Concentrations
Calculating Ion Concentrations
• Pg 386 #8
2.75g of MgO
2
75g of MgO (s) is added to 70 0mL of 2 40 mol/L HNO3(aq).
( ) is added to 70.0mL of 2.40 mol/L HNO
3( )
(a) Is the solution that results acidic or basic?
(b) What is the concentration of the ion that is responsible for the character of the solution?
REACTION: _________________________________________
Amount MgO (s) =
Amount MgO
Amount HNO3(aq) =
Since need 2 mol HNO3(aq) Æ
Th f
Therefore _________
i th li iti
is the limiting reactant
t t
(a) Is the solution that results acidic or basic?
(b) What is the concentration of the ion that is responsible for the character of the solution?
Homework
• Ch8.1 (pg 386) (pg
)
# 5‐7
Amount H3O+ (aq) =
• Ch8.1 review (pg387) #1‐3
Concentration H3O+ (aq) =
Interesting fact: What makes DNA an acid?
Interesting fact: What makes DNA an acid?
• Chapter 7 review for Wednesday
Chapter 7 review for Wednesday
• Homework Quiz Tuesday!