Monday
February 27, 2012
(Discussion and Worksheet
– Electrolytes and Nonelectrolytes)
Would the
light bulb
glow in this
picture?
Why or why
not?
??
Date
Date Date Into
Issued Due Grade
Book
Assignment
Currently Open
Summativ
e or
Formative
WS – Solubility
F
2/15
2/15
QUIZ – SOLUBILITY
S
2/17
2/17
WS – Types of Mixtures
F
2/21
2/24
WS - Solute – Solvent
Interactions
F
2/22
2/27
WS - Solutes: Electrolytes
and Non-electrolytes
F
2/23
2/28
QUIZ - MIXTURES
S
2/24
2/24
Last
Day
Announcements
I will be available this
afternoon until 4:45.
Begin Worksheet
Electrolytes and Nonelectrolytes
Solutes: Electrolytes and Non-electrolytes
Substances that dissolve in water are classified
according to whether they yield molecules or
ions in solution.
When an ionic compound dissolves, the positive
and negative ions separate from each other and
are surrounded by water molecules.
These solute ions are free to move, making it
possible for an electric current to pass through
the solution.
A substance that dissolves in water to give a
solution that conducts electricity is called an
electrolyte.
Solutes: Electrolytes and Non-electrolytes
Sodium chloride (NaCl) is an electrolyte, as
is any soluble ionic compound.
Certain highly polar molecular compounds,
such as hydrogen chloride (HCl), are also
electrolytes because HCl molecules form the
ions H3O+ and Cl- when dissolved in water.
By contrast, a solution containing neutral
solute molecules (such as sugar) does not
conduct electric current because it does not
contain mobile charged particles.
Solutes: Electrolytes and Non-electrolytes
A substance that dissolves in water to give a solution that does
not conduct an electric current is called a non-electrolyte.
Sugar is therefore a non-electrolyte.
The picture below shows an apparatus for testing the
conductivity of solutions.
Solutes: Electrolytes and Non-electrolytes
The electrodes are conductors that are attached to a power supply
and that make electrical contact with the test solution.
For a current to pass through the light bulb filament, the test
solution must provide a conducting path between the two
electrodes.
Solutes: Electrolytes and Non-electrolytes
A non-conducting solution is like an open switch between the
electrodes, and there is no current in the circuit.
The light bulb glows brightly if a solution that is a good conductor
is tested.
Such solutions contain solutes that are electrolytes.
Solutes: Electrolytes and Non-electrolytes
For a moderately conductive solution, however, the light bulb is
dim.
If the solution is a poor conductor, the light bulb does not glow at
all.
Such solutions contain solutes that are non-electrolytes.
Complete Worksheet
Electrolytes and Nonelectrolytes