1) Record the title in your notebook.
2) Read the passage and while reading...In your notebook, record ALL information that is underlined.
Solubility
Have you ever made Kool-Aid, hot chocolate, or had a lemonade stand? Chances are, you probably have. In
those three situations, you have encountered solubility. The root “solu” or “solv” means to “loosen up”.
When you make Kool-Aid and mix the flavored powder in water, you are loosening up the powder. Solubility
is the amount of material that can be dissolved into another material. When making Kool-Aid, hot chocolate,
and lemonade something is being dissolved into something else. The Kool-Aid powder, hot chocolate mix, and
lemon juice and sugar are all being dissolved into water.
The Kool-Aid powder, hot chocolate mix, and lemon juice and sugar are all types of matter than can be
dissolved easily in water. We called these materials solutes (sol-yoots). Solute is the matter that gets
dissolved into the solvent. Record two examples of solutes mentioned in this paragraph.
Solutes cannot be dissolved without water or another type of matter. You definitely need water to help out
with this! Since the water is the material that does the dissolving, we call it the solvent. Solvent is the matter
that dissolves the solute. Record water as an example.
When a solute is dissolved in a solvent, the combination is called a solution.
Draw and label the illustration below:
Here may be a way to remember the difference between solute and solvent:
There once was a burglar who was robbing a bank. He walked into the vault where the bank stored all of its
money. He accidentally set off the alarm! He knew that the police were coming, so he had to stash the money
somewhere that they wouldn’t find it and get out quickly. I looked all over the room for a secret way to hide.
Then, he saw a vent in the ceiling where the air conditioning came out. The robber hid the LOOT in the VENT.
The SOLUTE goes in the SOLVENT.
Real Life Science
Why is this important for us to know? Solubility is something we use in our daily lives. Think about it, we use
solubility when we cook, make hot tea on a cold winter day, make Kool-Aid for a picnic, make hot chocolate on
a snow day, and make a pitcher of lemonade on a hot summer’s day.
What Affects Solubility?
What do you think affects solubility? If I was feeling impatient and wanted to speed up the process of
solubility and dissolve my solute (sugar, salt, etc.) faster, what could I do??? I could possibly stir faster, but
there is something that can dissolve my solute even faster.
Let’s use our background knowledge! Think about what you know about atoms and molecules: How do atoms
and molecules move in hot temperatures? How do atoms and molecules move in cold temperatures? How do
you think temperature affects solubility? When the solvent (water) is heated, we know the molecules vibrate
faster and expand. When the solvent (water) is cooled, we know the molecules vibrate slower and contract.
Which temperature do you think increases or speeds up a solute being dissolved - hot or cold?
When a solvent (water) is heated, it increases or speeds up the solubility because the molecules are
vibrating faster and expanding. Therefore, the solute (sugar, salt, etc.) can dissolve faster! Heat always
increases the solubility of the solute.
Answer the following questions in your NOTEBOOK (not on this sheet):
Identify the solutes and solvent
1) Jaime poured salt into the water and stirred until the salt dissolved
solute ____________________
solvent ________________
2) Keily was freezing and wanted to make some hot cocoa. She emptied the packet of hot cocoa into
her hot cup of water.
solute ____________________
solvent ________________
3) Explain WHY Keily’s hot chocolate powder dissolved so fast? Be sure to explain the atoms’ motion
and movement.
4) When making a pitcher of lemonade you will need the following ingredients: a pitcher of water, a
small amount of lemon juice, and sugar. Which of the following ingredients are solutes?
a.
The pitcher of water ONLY
b.
The small amount of lemon juice ONLY
c.
Both the sugar and the small amount of lemon juice
d.
Both the sugar and the pitcher of water
5) What will increase the solubility of a solid in a liquid?
a.
Decrease in temperature
b.
Increase in temperature
c.
A solid can’t be dissolved in a liquid
d.
The rate at which you add the solid to the liquid