Transcript Chemistry Unit 02 Lesson 02

CHEMISTRY
Unit 02, Lesson 02
Classification of Matter
Fractional Distillation
Images source: http://en.wikipedia.org/wiki/Fractional_distillation
Separation Stations
Graphic Organizer Construction
• Construct a 3 tab graphic
organizer “Elements,
Compounds, and Mixtures”
– Materials:
•
•
•
•
1 sheet paper
scissors
pen
colored
pencils/crayons
• glue/tape
– Instructions:
• Fold paper lengthwise.
• Cut along the fold lines
from the edge to the
centerline.
• Color the headings
‘Elements’,
‘Compounds’, and
‘Mixtures’ different
colors.
• Use this graphic
organizer to list
examples of each type
of particle.
• Adhere graphic
organizer in your
science notebook.
Filtration
Separation
Technique
Filtration
Property Used for
Separation
Solubility
Example
Separate sand from
water
Thin Layer Chromatography
(TLC)
Chromatogram of 10
essential oils colored
with vanillin reagent.
Separation
Technique
Chromatography
Property Used for
Separation
Size, Polarity, pH
Example
Separate component
dyes of black ink
Sieving
Separation
Technique
Sieving
Property Used for
Separation
Particle Size
Example
Panning for gold (Au)
Magnetic Attraction
Separation
Technique
Magnetic Attraction
Property Used for
Separation
Magnetism
Example
Separate ferrous from
non-ferrous materials
Decantation
Separation
Technique
Decanting
Property Used for
Separation
Density or Solubility
Example
Pour off water from
sediment mixture
Evaporation
Separation
Technique
Evaporating
Property Used for
Separation
Solubility and Boiling
Point
Example
Driving off water
leaving salt behind
TASK: For the scenarios provided, use the decision tree
below, and your knowledge of matter, to classify the
particles (element, compound, or mixture) described.
An unknown, clear liquid is given to you in a
beaker. You transfer the liquid from the beaker to
a clean, empty test-tube and begin to heat it. After
a while, you see vapors (which on further
analysis, you discover are vapors of water) rising
from the test-tube, and pretty soon, all that's left
are a few crystals of salt stuck to the edges!
How would you classify the unknown liquid?
MIXTURE
You have won the world's biggest lottery,
for which you are given a huge block of
pure, metallic gold. How would you
classify this substance?
ELEMENT
A dish is given to you, which contains a blackishyellow powder. When you move a magnet over it,
you are amazed to see black particles (which you
find out are iron) fly upwards and get stuck to the
magnet. All that's left in the dish is a yellow
powder, which you discover to be sulfur.
How would you classify the initial blackishyellow powder?
MIXTURE
A substance is analyzed in a laboratory, and
when viewed under an electron microscope,
it is revealed that it contains only one kind of
atom. How would you classify the
substance?
ELEMENT
This gas is essential for us, and all other
aerobic organisms, to survive. We inhale it
along with the air we breathe (of which it
forms approximately 21%), and it then
helps in the oxidation of glucose in our
bodies. How would you classify the
substance?
ELEMENT
Water is what all life in the world depends
on.
How would you classify water?
COMPOUND
A magnesium ribbon is burnt in the air to
form the grayish oxide of magnesium magnesium oxide (MgO). How would you
classify this oxide?
COMPOUND
How would you classify the air we breathe?
MIXTURE
These are given 'symbols' like 'Ar', 'Zn', 'W‘,
and 'Xe' and are arranged in a table called
the periodic table. How would you classify
these substances?
ELEMENTS
An unknown, silvery powder has a
constant melting point and does not
chemically or physically separate into other
substances. How would you classify the
unknown substance?
ELEMENT
Separating an Unknown Mixture
1. Examine the mixture. Discuss, in your group, how you
are going to separate the mixture. Think about the
properties and techniques you will use and the order of
the steps that you will follow.
2. After you agree on a plan, write this plan in your
science notebook.
3. Review the plan with your teacher before you begin to
separate the mixture.
4. Using the techniques you have selected, separate the
mixture. Make observations and record them in your
science notebook.
Separating Mixtures
1. Were you successful in separating the components of
the mixture? Describe your results.
2. Was the order you used to separate the mixture
important? Why?
3. What was the most challenging part about separating
the mixture?
4. What properties did you use to separate the mixture?
Write a summary report that includes the
steps used to successfully separate the
unknown mixture into its components.
Include a table that:
• classifies each component separated as a pure
substance (element or compound) or mixture;
• identifies the property and technique used to
separate the component from the mixture; and
• indicates whether the property used is intensive or
extensive.