Mixtures and Solutions
Investigation 1
 What
is a mixture?
 What is a solution?
 What is the difference b/t a mixture and
solution?
 Our first investigation is figuring out what
a mixture is and what a solution is…
 What
are steps you can use to solve a
problem, a scientific or math problem?
 We just say in this class…
 Quincy Heard My Parrot Talk and Cackle
 What do you think that sentence might
actually mean?
 How
do you separate a mixture?
 Hypothesis
• List different ways you can separate a mixture.
• Use bullets to separate your ideas
• Add others ideas to your list
 This
powder stuff is the skeletal remains
of aquatic organisms called diatoms.
 These are pictures of diatoms. They are
small critters with “glass houses”.
 Gravel
 Diatomaceous
earth (powder)
 Salt (sodium chloride)
 Hand lenses
 Cups
 Sticky notes
 Syringe
 Craft sticks
 Water
 Paper towels
 What
are does the word property mean
when you are observing a substance?
 A property is
 List several properties of each of the
three substances. Use bullets
 Use your hand lenses
1.
2.
3.
4.
5.
6.
7.
8.
Label the cups, G, P, and S.
Put one level spoon of gravel in the G cup
Put one level spoon of powder in the P cup
Put one level spoon of salt in the S cup
Observe the materials and record your
observations in the chart.
Add 50 ml of water to each cup.
Stir the contents of each cup with the stick.
Observe what happens and record.
 Label
a second set of cups, G, P and S
 Your goals is to is to separate the
mixtures so that the water is in one cup
and the material is in another.
9. Use the screen and the filter paper to
see if you can separate the mixtures.
10. Write no or yes in the box if it works.
 The
screen is pretty simple to figure out.
 To make the filter work without making a
huge mess, fold the paper into fourths,
then open it to make a cone filter.
 Put
the saltwater solution on a window
sill, write your names on the cup
 Please rinse out and dry all the materials.
 Put all the materials back in your tub
 Clean and dry your table
 Put your journals away.
 Answer the questions on the back of your
lab sheet for the next class period.
 Mixture
– when you put two or more
materials together.
 What are everyday mixtures you use?
Brainstorm with your table and write your
ideas in your journal.
 Thinking of these three mixtures, how do
you think you can separate them? List
each mixture and how you plan to
separate the parts in your journal.
 Which
mixture was separated by the
paper filter?
 How are a screen and a paper filter
similar? How are they different?
Question: How can you separate salt and
water when in a solution?
Hypothesis: Write your hypothesis in your
journal.
 Will
a solution made with 50 ml of water
and a spoon of salt have the same mass
as 50 ml of plain water?
 More mass?
 Less mass?
 How can we find out?
Craft stick
 2 plastic cups
 2 evaporating
dishes
 1 container ½ liter
 1 syringe
 Water
 Electronic Scale or
TBB

1
 The
weight of the salt w/o water is ______
grams.
 The weight of the water w/o salt is ______
grams
 The weight of the water and salt is ______
grams
How can you determine the number of
grams of salt you put in the water to make
the solution.
• You separated the gravel from the water
and the powder from the water with
filters.
• How can you separate the salt from the
water?
• How can you get the salt back so you can
reuse it?
•
 How
could you separate the salt from the
water?
 Let’s try it!
 If the solid material in a mixture seems to
disappear in a liquid, and the mixture
can’t be separated from the water with a
filter, it is a special kind of mixture, called
a solution. Salt disappears or dissolves in
water to make a saltwater solution.
 Salt
is otherwise known as sodium
chloride.
 Crystal – the solid form of a materials
that can be identified by its properties,
such as shape, color, and pattern.
 Notice that all the salt crystals are
_______.
 Mixture
– two or more materials stirred
together
 Property – is a characteristic of an object,
something you can observe such as size,
color, shape, or texture
 Solution – is a special mixture formed when
a material dissolves in water
 Dissolve – a process in which one materials
disperses uniformly into another material,
so that the first material seems to disappear
 What
happened when the saltwater solution
evaporated?
 What is the material in the dish?
 What happened to the water that was in the
mixture?
 Does the salt look the same as it did
originally?
 Draw a sketch of what the crystals look like
in your journal – draw a circle and then the
crystals.
 Use your hand lens, and then check them
out under the dissecting microscope.
 How
would you separate
• Gravel and water?
• Powder and water?
• Salt and water?
 Evaporation
– when a liquid turns to a
gas by adding energy. The liquid
disperses in the air leaving any dissolved
material behind.
 Crystal – the solid form of a material that
can be identified by its properties, such
as shape, color and pattern.
 Question:
How can you separate a dry
mixture?
 We are going to mix the salt, gravel, and
powder in a cup – how can you separate
them?
 Hypothesis: Write yours down in your
journal.
1
spoon salt
 1 spoon gravel
 1 spoon
diatomaceous earth
 Screen
 Funnel
 Filter paper
 Cups
 Craft sticks
 Evaporating dishes
 Hand
lenses
 Spoons
 Syringes
 Water
 Paper towels
 tape
•Work with your table to come up
with a set of procedures to separate
everything out
•Write your procedures for
separating the mixtures so that the
salt is in one cup, the gravel is in a
second cup, and the DE is in another
cup
• Write your procedures using
numbers, 1 and 2 and so forth…
 Did
you do it?
 Write down a summary of how you
managed to separate the mixtures. This
is called the conclusion.
 What would you do differently next time
to make the experiment work better?
 Is there anything you would change?