Ch. 8
Solutions, Acids, & Bases
I. How Solutions Form
Definitions
 Types of Solutions
 Dissolving
 Rate of Dissolving

A. Definitions
– a mixture that has the same
composition throughout the mixture; a
homogeneous mixture.
 Solution
Solute - substance being
dissolved (in lesser
quantity)
Solvent – what the solute
is dissolved in (in greater
quantity)
A. Definitions
Solute - KMnO4
Solvent - H2O
Solutions
– a mixture that has the same
composition throughout the mix.
 Remember the difference between a
mixture and a compound.
• Compounds have a fixed composition
throughout.
• Mixtures can have a variable
composition throughout.
 Solution
A. Definitions
– The maximum amount of
solute that can be dissolved in the
solvent at a given temperature.
 Solubility
B. Types of Solutions
solutions –
maximum amount of solute at a
given temperature.
Saturated
solutions – less
than the maximum amount of
solute at a given temperature.
Unsaturated
solutions –
more than the maximum amount
of solute at a given temperature;
unstable.
Supersaturated
B. Types of Solutions
UNSATURATED
SOLUTION
more solute
dissolves
SATURATED
SOLUTION
no more solute
dissolves
concentration
SUPERSATURATED
SOLUTION
becomes unstable,
crystals form
C. Dissolving
 Solvation
• occurs at the surface of the solute
• solvent particles surround solute
particles (+/- attraction)
• solute particles are pulled into solution
D. Rate of Dissolving
 Solids
dissolve faster...
• more stirring
• small particle size
(increased surface area)
• high temperature
Rate of Dissolving
To increase rate of dissolving of SOLIDS:
Heat
it
Crush
Stir
it
it
D. Rate of Dissolving
 Gases
dissolve faster...
• no shaking or stirring
• high pressure
• low temperature
To
make a gas dissolve more
quickly in a liquid:
• Cool it
• Increase the pressure
of the gas
Ch. 8
Solutions, Acids, & Bases
II. Concentration & Solubility
A. Concentration
%
by Volume
• usually liquid in liquid
• Ex: 10% juice = 10mL juice + 90mL water

% by Mass
• usually solid in liquid
• Ex: 20% NaCl = 20g NaCl + 80g water
A. Concentration
 Concentrated
solution
• large amount of solute
 Dilute
solution
• small amount of solute
B. Solubility
 Solubility
• maximum grams of solute that will
dissolve in 100 g of solvent at a given
temperature
• varies with temperature
• based on a saturated solution
B. Solubility
 Solids
are more soluble at...
• high temperatures

Gases are more soluble at...
• low temperatures
• high pressures
(Henry’s Law)
C. Solubility Charts
Reading Solubility Charts
• If the number in the problem is EQUAL to
the value on the chart the solution is
considered SATURATED
• If the number in the problem is LESS than
the value on the chart the solution is
considered UNSATURATED
• If the number in the problem is MORE than
the value on the chart the solution is
considered SUPER SATURATED
C. Solubility Charts
Solubility of Compounds in g/100g of
Water at various Temperatures
Compound
0◦ C
20◦ C
60◦ C
100◦ C
Ammonium chloride
Copper(II) sulfate
Lead(II)chloride
Potassium bromide
Sodium chlorate
29.4
23.1
0.67
53.6
79.6
37.2
32.0
1.0
65.3
95.9
55.3
61.8
1.94
85.5
137
77.3
114
3.2
104
204
Answer Questions on your paper

Chart
1) How would you classify a solution of 65.3g of
Saturated
potassium bromide at 20ºC? _________
2) How would you classify a solution of 65.3g of
Unsaturated
potassium bromide at 60ºC? ____________
3) How would you classify a solution of 65.3g of
Supersaturated
potassium bromide at 0ºC? ______________
4) How would you classify a solution of 37g of
ammonium chloride at 20ºC? Unsaturated
___________
5) How would you classify a solution of 2.5 g of
Supersaturated
lead (II) chloride at 20ºC? ______________
D. Solubility Graphs
 Solubility
Curve
• shows the
dependence of
solubility on
temperature

Graph
6) How would you classify a solution of 80g
Supersaturated
of HCl at 20ºC? ____________
7) How would you classify a solution of 30g
of KNO3 at 20ºC? Unsaturated
__________
8) How would you classify a solution of 39g
Saturated
of NaCl at 100ºC? ________
9) How would you classify a solution of 80g
Unsaturated
of NaNO3 at 30ºC? __________
10)How would you classify a solution of 40g
of KClO3 at 80ºC? __________
Unsaturated
11)How many grams of solute would you
need to form a saturated solution of NH4Cl
50 g
at 50ºC? _____
12)How would you classify a solution of 20g
Unsaturated
of SO2 at 0ºC? ___________
13)How much KI would you need to form a
135 g
saturated solution at 10ºC? _____
14)Which solid decreases in solubility as the
temperature increases? Na
_______
2SO4
Acid, Bases & Salt Video

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Pre Test
True
False
True
True
False
False
True
True
False
False

1.
2.
3.
4.
5.
6.
7.
8.
9.
Post Test
Neutralization
Base
Anion
Electrolytes
False
False
True
False
False

10.
11.
12.
Post Test
bitter, slippery, high
pH
Acids donate
hydrogen, Bases
accept Hydrogen
An easy way to
gauge is something
is a strong/weak
acid or base
Ch. 8
Solutions, Acids, & Bases
III. Particles in Solution
“Like Dissolves Like”
 Electrolytes

A. “Like Dissolves Like”
 Polar
substances will only dissolve in polar
liquids
• Rubbing alcohol and water
 Nonpolar substances will only dissolve in
nonpolar liquids
• Oil and butter
 Substances that aren’t the same don’t mix.
• Oil and water
A. “Like Dissolves Like”
NONPOLAR
POLAR
NONPOLAR

Detergents
• polar “head” with long nonpolar “tail”
• can dissolve both types (polar and nonpolar)
POLAR
B. Electrolyte
 An electrolyte is a substance that when
dissolved in water form ions
 Electrolytes get their name from the fact
that the conduct electricity in water.
 Example: salt dissolved in water
 Many sports drinks contain
“electrolytes” which are salts dissolved
in water
B. Electrolytes
- +
-
salt
Electrolyte
solute exists as
ions only
Easily conducts
electricity
- +
+
acetic acid
sugar
Weak
Electrolyte
NonElectrolyte
solute exists as
ions and
Molecules
Slightly conducts
electricity
solute exists as
molecules only
Does NOT
conduct electricity
B. Electrolytes
 Dissociation
• separation of +/ions when an ionic
compound
dissolves in water
B. Electrolytes
 Ionization
• breaking apart of
polar covalent
molecules into
ions when
dissolving in water
Ch. 8
Solutions, Acids, & Bases
IV. Intro to Acids & Bases
Definitions
 Properties
 Uses

A. Acids
• Acids contain at least one hydrogen
atom that can be removed when the
acid is dissolved in water.
• These form hydronium ions, H3O+.
• Also called a proton donor
HCl + H2O 
+
H3O
+
–
Cl
A. Bases
• Bases form hydroxide ions (OH-) in
a water solution.
• a proton acceptor
NH3 + H2O 
+
NH4
+
OH
A. Indicators
• Indicators are an organic substance
that changes color in an acid or base.
 Examples:
•
•
•
•
litmus - red/blue
phenolphthalein - colorless/pink
goldenrod - yellow/red
red cabbage juice - pink/green
B. Properties
 sour
 pH
taste
less than 7
 bitter
 pH
taste
greater than 7
 corrosive
 corrosive
 electrolytes
 electrolytes
 turn
 turn
litmus red
litmus blue
with metals to  slippery feel
form H gas
 react
C. Uses
–phosphoric acid - soft drinks,
fertilizer, detergents
 H2SO4 – sulfuric acid - fertilizer, car
batteries
 HCl – hydrochloric acid - gastric juice
 HC2H3O2 – acetic acid - vinegar
 H3PO4
C. Uses
– sodium hydroxide -lye, drain
and oven cleaner
 Mg(OH)2 – magnesium hydroxide laxative, antacid
 NH3 –ammonia - cleaners, fertilizer
 NaOH
Ch. 8
Solutions, Acids, & Bases
V. Strength of Acids & Bases
Strength vs. Concentration
Strong vs. Weak
 pH

A. Strength vs. Concentration
and weak – tells how easy the
acid or base dissociates in solution.
 Concentration – The amount of acid or
base in a solution.
 Strong
 It
is possible to have a dilute concentration
of a strong acid that would be less harmful
than a concentrated weak acid.
A. Strength of Acids & Bases
 The
strength of an acid or base depends
on how completely a compound
separates into ions when dissolved in
water.
 Ions can carry an electric charge so a
strong acid will carry more electricity than
weak acid.
B. Strong vs. Weak
 Strong
-
+
 Weak
-
+
Acid/Base
• 100% ions in water
• strong electrolyte
• HCl, HNO3, NaOH, LiOH
Acid/Base
• few ions in water
• weak electrolyte
• HC2H3O2, NH3
B. Strong Acids
 Acids
that ionize almost
completely in a solution
are strong acids.
 Ex: HCl, HNO3, and
H2SO4
 They have a very low pH
(0-1).
B. Strong Bases
 Bases
that dissociate completely in a
solution are strong bases.
 Ex: NaOH
 They have a very high pH (13-14)
C. pH Scale
 pH
(potential of Hydrogen)
• a measure of the concentration of H+
ions in a solution
• measured with a pH meter or an
indicator with a wide color range (0-14)
14
0
7
INCREASING
ACIDITY
NEUTRAL
INCREASING
BASICITY
C. pH Scale
pH of Common Substances
ConcepTest
 Which
of the following "molecular"
pictures best represents a concentrated
solution of the weak acid HA?
A
B
ConcepTest
 Is
the following statement TRUE or
FALSE?
• A strong acid has a lower pH than a
weak acid.
• True• But: Strong/weak refers to amount of
ionization whereas pH refers to
concentration of H+.
Ch. 8
Solutions, Acids, & Bases
VI. Neutralization

Neutralization Reaction
A. Neutralization Reaction
 Chemical
reaction between an acid and
a base.
 Products are a salt (ionic compound)
and water.
A. Neutralization Reaction
ACID + BASE  SALT + WATER
HCl + NaOH  NaCl + H2O
=
Neutralization does not always mean pH = 7.
A. Neutralization Reaction
KOH + HNO3  H2O + KNO3
Acid
HNO3
Base
KOH
Salt
KNO3