Download + H 2 O

Acids
Lesson 2
Strong and Weak
Bases
Strong Acids
Weak Acids
HONORS ONLY!
Ionization Constants for Acids/Bases
Acids
Increase
strength
Conjugate
Bases
Increase
strength
Strong and Weak Acids #1
HCl + H2O —> Cl- + H3O+
HA + H2O
Chapter 15-2004
A- + H3O+
4
Strong Acids
Completely ionize in water
Have very large Ka’s.
Produce large amounts of H3O+.
Weak Acids
Left side of the Acid Chart below the top six.
Do not completely ionize in water.
Are poor conductors.
Produce small amounts of H3O+.
Have small Ka’s.
Use a “⇄” and not “”
HF + H2O ⇄ H3O+
+
F-
[H3O+][F-]
=
3.5 x 10-4
[HF]
Water is not included because it is a pure liquid!
Its concentration is constant!
Ka
=
from page 6
Strong Bases- yellow
LiOH
NaOH
KOH
RbOH
CsOH
FrOH
Ra(OH)2
Sr(OH)2
Ba(OH)2
Arrhenius Bases
Weak Bases- blue
completely ionize but,
very low solubility
Ca(OH)2
Mg(OH)2
Weak Basesmost other metals
Be(OH)2
Zn(OH)2
AgOH
Arrhenius Bases
Strong Bases
Strong bases completely ionize in water to produce OHThere are 9 Arrhenius strong bases - Group I & heavy Group II hydroxides
LiOH

Li+
+
OH-
KOH

K+
+
OH-
Sr(OH)2

Sr2+
+
2OH-
Ra(OH)2

Ra2+
+
2OH-
Note all bases make OH-
 means strong
Bronsted Bases
bases
Increasing strength
acids
Weak Bases-blue
SO32NH3
CNCO32-
PO43-
Strong Bases- yellow
O2-
NH2-
There are two more Bronsted type strong bases. They are
found on the right highlighted area of the acid chart -p 6.
O2-
H+
+
H2O

OH-
NH2-
H+
+
H2 O

NH3
Again, all bases make OH-
 means strong
+
+
OH-
OH-
Arrhenius Weak Bases
A weak base is one that partially reacts with water
to produce OH-.
Be(OH)2(s)
⇄
Be2+
+
2OH-
Zn(OH)2(s)
⇄
Zn2+
+
2OH-
Bronsted Weak Bases:
F-
H+
+
H2 O
⇄
HF
+
OH-
H2O
⇄
HC2O4-
+
OH-
⇄
H2CO3
+
OH-
H+
C2O42-
+
H+
HCO3-
+
H2 O
H+
C6H5O73-
NH3
+
H2O
⇄
HC6H5O72-
+
OH-
H+
+
H2O
⇄
NH4+
+
OH-
They all make OH- by accepting a proton from water!
Strong, weak
Concentrated, Dilute
ACID BASE
STRONG/
WEAK
CONCENTRA
TED /DILUTE
Shift in acid base
equilibrium solution
Which direction will an Acid-Base
equilibrium reaction move?
Mix equal amounts of all species what happens?
?
H2SO4(aq) + NH3(aq)
NH4+ aq) + HSO4-(aq)
Stronger Acid Stronger Base
HCO3-1(aq)
+
SO4-2(aq)
Wkr Acid Wkr Base
?
Wkr Acid
Wkr Base
HSO4-1(aq) + CO3-2(aq)
Stronger Acid
Chapter 15-2004
Stronger Base
18
Conductivity of Acid and Bases
The conductivity of an acid is determined by the
number of ions generated in a solution and is therefore
a combination of both the strength and
concentration of the acid.
1.0 M HCl is a better conductor than 0.10 M HCl
1.0 M HI is a better conductor than 1.0 M HF.
1.0 M HF has the same conductivity as 0.02 M HCl.
Equations
SA+ SB 
SA + WB 
WA + SB 
WA + WB 
Workbook page 125
Question # 24-25
Acids
Lesson 3
Acid and Base
Reactions
In Chemistry 11
H2SO4
+
2KOH

In Chemistry 11
H2SO4
+
2KOH

K2SO4 +
2HOH(l)
In Chemistry 11
H2SO4
+
2H+ + SO42-
2KOH

K2SO4 +
2HOH(l)
In Chemistry 11
H2SO4
+
2KOH

2H+ + SO42- + 2K+ + 2OH- 
K2SO4 +
2HOH(l)
In Chemistry 11
H2SO4
+
2KOH

K2SO4 +
2H+ + SO42- + 2K+ + 2OH-  2K+ +
2HOH(l)
SO42-
+
In Chemistry 11
H2SO4
+
2KOH

K2SO4 +
2H+ + SO42- + 2K+ + 2OH-  2K+ +
2HOH(l)
SO42-
+ 2HOH(l)
In Chemistry 11
H2SO4
+
2KOH

K2SO4 +
2H+ + SO42- + 2K+ + 2OH-  2K+ +
H+ + OH- 
2HOH(l)
SO42-
HOH(l)
Use an arrow if you have a strong acid or a strong base!
Strong acids, strong bases, and soluble salts are ionized!
+ 2HOH(l)
In Chemistry 12
H2C2O4
+
2KOH
In Chemistry 12
H2C2O4
+
2KOH 
In Chemistry 12
H2C2O4
+
2KOH 
K2C2O4
+
2HOH(l)
In Chemistry 12
H2C2O4
+
2KOH 
H2C2O4
+ 2K+ + 2OH-  2K+ +
K2C2O4
+
2HOH(l)
C2O42- + 2HOH(l)
In Chemistry 12
H2C2O4
+
2KOH 
H2C2O4
+ 2K+ + 2OH-  2K+ +
H2C2O4
+ 2OH-

K2C2O4
+
2HOH(l)
C2O42- + 2HOH(l)
C2O42- + 2HOH(l)
The weak acid or base does not dissociate!
Break up strong acids, strong bases, and soluble salts!
Conductivity
Good Conductors
Weak Conductors
Nonconductors
Strong Acids Strong Bases Soluble Salts
HCl
NaOH
KCl
Weak Acids
Weak Bases
Low Solubility Salts
HF
Zn(OH)2
AgCl
Molecular covalent
C12H22O11
In Chemistry 12
H+
H+
HC2O4Acid
+
HCO3Base
⇋
C2O42-
Base
+ H2CO3
Acid
Weak acids and weak bases react but do not go to completion (⇋)
The higher one on the acid side of the chart will be the acid and donate
a proton.
Label all acids and bases- note H2C2O4 donates in the reverse reaction
The acid on the left HC2O4- is stronger than H2CO3 so the other side or
the products are favoured.