Download Mixture - Net Start Class

Investigate (09/10/13)
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In your Notebook, prepare a data table like
the one on page 121 for all 6 substances. No
column for filter exercise!
Work with the students at your table.
Follow the instructions on page 120 -121,
start with 3) do not do last bullet.
Warm up(09/10/13)
Pure Substances vs Mixtures
Look at each picture below, and for each item, be prepared to answer
Is it a mixture or a compound? Is it a solution?
Is it a suspension? Is it a colloid? Is it homogeneous or heterogeneous?
How can we tell the difference?
How are mixtures similar or different from compounds?
Write down the items below and tell which is a
mixture and which is a
Matter and Change
Chemistry
Physical Changes

Physical change: a change in the
physical properties of a substance.

Composition does not change.

Phase changes (like liquid to gas)
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
Evaporation, freezing, condensing, subliming, etc.
Tearing or cutting the substance
Chemical Change
A change that produces matter with a
different composition than the original
matter.
 Atoms rearrange themselves into new
combinations.
 All chemical reactions

Burning of Methane
CH4 +2O2 CO2 + 2H2O
Recognizing a Chemical Change
1.
2.
3.
4.
5.

permanent color change
gas produced (odor or bubbles)
precipitate (solid) produced
light given off
heat released (exothermic) or
absorbed (endothermic)
examples include
decomposing, rusting, exploding,
burning, or and oxidizing.
Quick Quiz
When one substances turns into another, what kind of change has
taken place?
A.
B.
C.
D.
chemical reaction
physical reaction
extensive reaction
nuclear reaction
Change of Phase
Melting
Condensation
solid
gas


liquid
liquid
Freezing
liquid

solid
Evaporation
Sublimation
liquid
solid


gas
gas
Boiling: Evaporation occurring beneath the
liquid’s surface.
Temperature vs Time
Phase Change Graph
Is changing phase a physical
or chemical change?
Pure Substance
Matter that has a uniform and
definite composition.
Elements- cannot be broken down
chemically into simpler substances
Compounds- all the components are the
same (but could be chemically broken down
into elements)
Water is a compound.
All the
components are the
same—H2O
molecules.
Mixture: a physical blend of two or more
substances that are not chemically combined.
Homogeneous-mixture has the same
properties/composition throughout.
Homogeneous means the particles are evenly distributed
HeterogeneousNot uniform composition
Mixtures can be physically separated.
Mixtures exhibit physical properties
similar to the components of the mixture.
Homogenous Mixtures
Solutions

A solution is a
homogeneous mixture
formed when one
substance dissolves in
another.

It is the best mixed of all
mixtures.

The substance that is
dissolved is the solute and
the substance that does
the dissolving is the
solvent.
Heterogenous Mixtures
Colloids
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Colloids are mixtures, and look like solutions,
but their particles are too small to settle to the
bottom of their container over time.
Colloids can not be filtered out.
Colloids obey the Tyndall effect

the particles are mixed together but not
dissolved

Examples of colloids are mayonnaise, egg
whites, and gelatin.
Heterogenous Mixtures
Tyndall effect


Tyndall effect is
occurring if you shine a
flashlight through a jar
of liquid and see the
light beam.
This distinguishes a
colloid from a solution.
Heterogenous Mixtures
Suspensions
In a mixture called a suspension the
particles are very large and will
settle out upon standing.
Suspensions can be filtered.
Examples include muddy water,
sand in water, paint, dust in air,
flour in water
Muddy water, will settle when it is left still for a period
of time.
Types of mixtures

How can you tell the difference between a
solution, a colloid and a suspension?
First, try filtering it, then look for the Tyndall effect.
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Mixtures can be physically separated.
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Mixtures exhibit physical properties
similar to the components of the
mixture.

To separate, use differences in the
physical properties of the components
of the mixture.
Filtration: separates a solid from a
liquid in a heterogeneous mixture
Distillation:
-separate dissolved solids from a liquid
-uses boiling and condensation.
Learning Check
Identify if the following are
1) Homogeneous or 2) Heterogenous
1.
2.
3.
1 perfect, pure air 4. 2 salad dressing
1 ink
5. 1 coffee
1 soft drink
6. 2 Chicken
noodle
soup
Learning Check
Circle the solute and underline the solvent
50 g of water and 5 g NaCl
2. 2. 20 g copper and 50 g zinc
3. 30%water and 70% alcohol
4. 18.0 L of nitrogen & 12.0 L of oxygen
1.
Warm up
Pure Substances vs Mixtures
Look at each picture below, and for each item, be prepared to answer
Is it a mixture or a compound? Is it a solution?
Is it a suspension? Is it a colloid? Is it homogeneous or heterogeneous?
How can we tell the difference?
How are mixtures similar or different from compounds?
9-9-2013
Write down the items below and tell which is a
mixture and which is a
Today’s Activity
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
Read Chem Talk on page 122
Draw either a Venn Diagram or table that
compares solutions, suspensions and
colloids.
Tomorrow night is OPEN HOUSE !!
Please remind your parents!