Solutions
Solution

A solution is a
homogeneous mixture
in which one substance
is dissolved in another
substance
Components of a solution

Two parts of a
solution: the substance
being dissolved
(solute) and the
substance doing the
dissolving (solvent)
Aqueous solution

Solutions in which the
solvent is water are
aqueous solutions
(most common)
Tinctures

A solution in which the
solvent is alcohol is a
tincture Ex: iodine
tincture
Characteristics of a solution
Mixture of two or more
substances
 light passes through it
 particles are uniformly
distributed

Ions and dissociation

Ions are atoms with a
positive or negative
charge
Electrolytes

Solutions that conduct
electricity are
electrolytes (sodium
chloride and silver
nitrate)
Non-electrolytes

Non-electrolytes form
solutions that do not
conduct electricity
(sugar, alcohol,
benzene)
Questions
What is a solution?
 What are the two parts
of a solution?
 What are three
properties of a
solution?

Questions

What’s the difference
between an aqueous
solution and a tincture
Question

If you wanted to
dissolve a substance in
water as quickly as
possible what could
you do?
Ways to increase dissolving rate

In order to increase the
rate in which a solution
dissolves one could
heat the solution, stir
it, or crush the solute
particles
Solubility

The measure of how
much solute can be
dissolved in a solvent
is solubility
What affects solubility?

The three main factors
that affect solubility
are temperature, type
and the amount of the
solvent
Effervescence (fizz)

The escape of a gas
from a liquid is
effervescence
(example: soda and
alka seltzer)
Concentration

Concentration of a
solution is the amount
of solute that is
dissolved in a solvent
Concentrated vs. dilute
A solution with a lot of
solute dissolved is
concentrated
 A solution with a little
solute dissolved is
dilute

Types of solutions
A saturated solution
contains all the solute
it can possibly hold
 An unsaturated
solution contains less
solute that is possible

Supersaturated solution

A supersaturated
solution can be made
to hold more solute
than is normal
Question

Compare a saturated,
unsaturated, and a
supersaturated
solution
Questions
What is solubility and
what are the three
factors that affect it?
 What are three ways to
increase the rate in
which a solute
dissolves?

Water
Water is the universal
solvent
 A substance that
cannot dissolve in
water is insoluble

Polar vs. non-polar
A polar molecule has
oppositely charged
ends (+ and -)
 Non-polar molecules
have the same charges
on its ends

Rule for dissolving solutes in a
solvent
 Like solutes dissolve in
like solvents (polar in
polar, non-polar in nonpolar)
Hard water vs. soft water
Hard water contains
dissolved metal ions
 Soft water does not
contain dissolved
metal ions

Freezing point depression

Lowering the freezing
point of a solution as a
result of the dissolved
solute (freezing point
depression) Ex:
antifreeze in water
Boiling point elevation

Raising the boiling
point of a substance by
adding solute (salt in
water)
Questions
What is the difference
between polar and nonpolar molecules?
 What is the general
rule for dissolving
solutes?

Questions
What is the difference
between hard and soft
water?
 How does a solute
affect the freezing
point and the boiling
point?

Suspension

A suspension is a
heterogeneous mixture
in which the solute
particles are large
enough to be seen
(solute is suspended)
Colloid

A colloid is a
homogeneous mixture
that is not a true
solution (does not
separate, solute
remains suspended)
Acids

Properties of an acid:
sour taste, affecting
the color of indicators,
turn litmus paper from
blue to red, pH 1-6.9
Weak acids vs. strong acids
Weak acids (pH 4 - 6.9)
 Strong acids (pH about
1-3; common acids:
sulfuric, hydrochloric,
nitric, and acetic acids

Bases
Bases are slippery,
bitter taste, turn litmus
paper from red to blue
 pH 7.1-14

Bases

Common bases
potassium hydroxide,
calcium hydroxide,
sodium hydroxide, and
ammonium hydroxide
Weak bases vs. strong bases
Weak bases (7.1-10.9
pH)
 Strong bases (11-14
pH)

pH scale
 Measures hydronium
ion concentration
(strength of the acid or
base)
 pH scale ranges from
0-14 (7 is the neutral
point) water
Salt

Salt is a compound
formed when an acid is
mixed with a base
(positive ion from a
base and a negative
ion from an acid)
Neutralization

A neutralization
reaction occurs when
an acid and a base
combine to form salt
and water
Precipitate

A precipitate is an
insoluble substance
crystallizes out of
solution (ex: salt from
a neutralization
reaction)
Precipitation reaction

The process of forming
a precipitate is
precipitation
Questions
What is the pH scale
used for?
 What is the pH range
for an acid, a base?

Questions
What are some
properties of an acid?
Of a base?
 Describe neutraliztion.
 What is a salt?
