Classification of Matter
and Solutions Notes
Part 1
I. Classification of Matter
Yes
Matter
Can it be physically separated?
Mixtures
Is the composition uniform?
Yes
Homogeneous
Mixtures
(Solutions)
(air, sugar water,
salt water)
No
Heterogeneous
Mixtures
(Suspensions
or Colliods)
(granite, wood,
muddy water)
No
Pure Substances
Can it be decomposed by an
ordinary chemical reaction?
Yes
No
Compounds
Elements
(water, sodium
chloride, sucrose)
(gold, oxygen,
carbon)
Mixtures: matter that can be physically
separated into component parts.
 a. homogeneous mixture –has uniform
composition; also called a solution
 b. heterogeneous mixture – does not
have a uniform composition; suspensions
or colloids

Pure Substances: when component parts of a
mixture can no longer be physically separated
into simpler substances. Pure substances are
either compounds or elements.
 a. Compounds – can be decomposed by a
chemical change.
 b. Elements – cannot be decomposed by a
chemical change.

II. Types of Mixtures (Solutions,
Suspensions, and Colloids) Table 13-3 page
398
1. Solution (homogeneous mixture)- any
substance (solid, liquid, gas) that is evenly
dispersed throughout another substance. Ex:
sugar water, salt water (do not scatter light)
Components of a Solution
 1. Solute – substance dissolved
 2. Solvent – substance that does the dissolving

(water is the universal solvent)
2. Suspensions (heterogeneous
mixtures) – particles in a solvent are so
large that they settle out unless the
mixture is constantly stirred Ex: muddy
water, vegetable soup, page 398 (may
scatter light, but are transparent)
3. Colloids (heterogeneous mixtures)
– particles are intermediate in size
between those in solutions and
suspensions. Example: After large soil
particles settle out of muddy water the
water is often still cloudy because colloidal
particles remain dispersed in the water.
Ex: milk, mayonnaise , page 398 (do
scatter light – Tyndall Effect)
III. The Solution Process (Solvation)
Solvation is the process by which a solute
dissolves in a solvent.
Miscible: when solutes and solvents are
soluble in each other (solvation occurs)
Immiscible: when solutes and solvents
are not soluble in each other (solvation
does not occur)
Aqueous solutions – solvent is water.
IV. Like Dissolves Like
We don’t always use water as the solvent!
Solutions can be made from various
substances – a rule of thumb to follow
when trying to determine if two
substances will form a solution is “like
dissolves like.”
Solubility: the maximum amount of a
substance that will dissolve in a solvent (at
a specific temperature)
According to solubility, solutions can be
either:
unsaturated – a solution that is able to
dissolve more solute (not enough)
saturated – a solution that cannot dissolve
any more solute (just enough)
supersaturated – a solution that contains
more solute than can be dissolved (too
much!!)
The solubility of substances varies widely.
For example 0.189 grams of Ca(OH)2
dissolves in 100 grams of water at 0C.
122 grams of AgNO3 dissolves in 100
grams of water at 0C. (page 404 in your
book)
VI. Factors Effecting Rate and
Solubility
A.
Factors Effecting Rate:
1. Agitation – stirring or mixing the solution will
increase the rate or how fast the solute
dissolves, but it will not change how much
solute can be dissolved. If you add 35.9 grams
of salt to water (at 20C) it will all eventually
dissolve, but if you stir the solution it will
dissolve much quicker. (As you stir the particles
are constantly being moved, allowing for
interactions between solute and solvent to occur
more quickly.)
2.
Surface Area – increasing the surface
area of the solute will increase the rate or
how fast the solute dissolves, but it will
not change how much solute can be
dissolved.
3. Temperature – increasing temperature
will increase the rate or how fast the
solute dissolves in the solvent. (As
temperature increases the particles begin
to move faster and faster and collide with
more particles quicker, which means the
solute and solvent particles have an
increased chance of coming into contact
with each other.)
B. Factors Effecting Solubility:
1. Increasing Temperature - solubility of
a solid solute in a liquid solvent generally
increases with an increase in temperature.
At 20C 35.9 grams of salt will dissolve in
100 grams of water, but at 100 C 39.2
grams of salt will dissolve in 100 grams of
water!
2. Decreasing Temperatureincreases the solubility of a
gaseous solute in a liquid
solvent. What would you
rather drink, a hot coke or a
cold coke?
3. Pressure – The solubility of a gas
increases as the pressure of the gas
above the liquid increases.
Carbonated drinks have CO2
dissolved in them. They are also
bottled under a high pressure of CO2,
which forces the CO2 into solution.
When the bottle is opened, the
pressure above the solution
decreases, and bubbles of CO2 form
in the liquid, then escape. Eventually,
most of the CO2 escapes and the
drink becomes “flat.”
Henry’s Law- “At a given
temperature, the solubility, S,
of a gas in a liquid is directly
proportional to the pressure,
P, of the gas above the
liquid.”
S1 = S2
P1
P2
VII. Electrolyte VS
Nonelectrolyte
1. Electrolyte – compounds that conduct
an electric current in an aqueous solution
OR in the molten state. An electrolyte
solution contains charged particles (ions),
which can move. Any salt dissolved in
water is an electrolyte: NaCl, KI, etc.
Some polar molecules also conduct
electricity (most acids are electrolytes
because H is the only nonmetal that has a
+ charge).
Types of Electrolytes
1. Strong electrolytes – a large portion
of the solute exists as ions:
a. aqueous solutions of all ionic compounds
b. strong acids: have at least 2 oxygens per
hydrogen (H2SO4, HNO3)
c. strong bases – these are hydroxides from
Group I and II, except Be. (NaOH, CsOH,
etc)
2. Weak electrolytes – these are solutions in
which only a small portion of the solute exists
as ions
a. weak acids:
-all binary acids – HF, H2S, etc
-weak acids that have less than 2 oxygen's per
hydrogen
b. weak bases – hydroxides of everything else not
in Group I or II, including Be(OH)2
2. Non-Electrolytes- compounds that do
NOT conduct electricity in either aqueous
solution or when melted:
 distilled water
 gases
 molecular compounds (2 nonmetals)
 organic compounds – alcohols, sugars,
etc. anything containing a Carbon
Practice Problems: Tell whether each of the
following aqueous solutions would be a
STRONG, WEAK, or NON electrolyte.
1. NaCl
2. CH3Br (l) 3. HMnO4
4. HC2H3O2
5. LiOH
6. HC6H7O6
7. CO2 (l)
8. HF
VIII. Concentration: the concentration
of a solution is a measure of the amount
of solute in a given amount of solvent or
solution.