SJ #1 “Solubility” Lesson 12: Notes & Lab
Observations:
1)
2)
3)
(Keep these properties in mind: phase, color, transparency, thickness,
etc. when you make your observations—be specific)
MIXTURE
a combination of substances in the same place that
are NOT chemically combined
EX: trail mix, air,
SOLUTION: a “very well-mixed” mixture of 2 or more
substances, called a “homogenous” mixture
-still NOT chemically mixed
EX: lemonade, shampoo
(you CANNOT see individual particles)
DISSOLVE: when one substance appears to absorb another
substance, but they do NOT chemically combine
--they only mix physically (physical change)
--they CAN be separated
SOLUBLE:
when a substance dissolves in another substance,
it is called a SOLUBLE SUBSTANCE
INSOLUBLE: when a substance does NOT dissolve in another
substance, it is an INSOLUBLE SUBSTANCE
SOLVENT: the substance that dissolves another substance
EX: water
--usually present in larger amount
SOLUTE: the substance that gets dissolved
EX: salt
--usually present in smaller amount
***Solvents and solutes can be ANY PHASE
EX: --salt (S) in water (L) (most common)
--oxygen (G) in water (L)
--metal (S) with metal (S)  alloys (melted together first)
--air: gasses (G) dissolved in nitrogen (G)
ELECTROLYTES: solutions that conduct electricity; salts
NON-ELECTROLYTES: cannot conduct electricity; non-salts
AQUEOUS SOLUTION: when water is the solvent
POLAR MOLECULE: a molecule that has electrically charged
parts, but is electrically neutral as a whole
EX: water = H2O
2 hydrogens & 1 oxygen
+
H
H
O
--“LIKE dissolves LIKE”
--polar dissolves polar
--nonpolar dissolves nonpolar
--polar and nonpolar do NOT mix well = “IMMISCIBLE”
(water + oil)
SOLUBILITY: the amount of solute that can dissolve in a given
amount of solvent, measured in (g/L)
*Solubility changes with temperature.
**At room temperature, a solvent can dissolve only a certain
amount of solute
*As temperature of a liquid increases, the solubility of a solid
solute increases.
EX: salt in water  more salt dissolves in warmer water
than in colder water
DILUTE SOLUTION: a weak solution with not very much solute
CONCENTRATED SOLUTION: a strong solution with a lot of
solute
SATURATED SOLUTION: when a solvent cannot dissolve any
more solute
UNSATURATED SOLUTION: when a solvent can still dissolve
more solute
SJ #1 Solubility LAB
Problem: What happens to the solid when mixed with water?
Materials:
*test tube rack
*paper towel
*GOGGLES
*chemicals in cups
*copper sulfate
*zinc oxide
*powdered sugar
*5 test tubes (A-E)
*100 mL graduated cylinder
*water
*lab scoops
*sodium chloride
*corn starch
Procedure:
1) Get materials and find an open space to work with your group.
2) Place ONE SCOOP of each chemical into the
corresponding test tube (A-E).
3) Add 20 mL of water to each test tube.
4) Hold the test tube with your thumb and paper towel to shake
the MIXTURE up and down 20 times. Place the test tube
back in the rack so the particles can settle.
5) Repeat steps 3-4 for each chemical.
6) Once particles have settled, write at least 3 observations for
each chemical in the data table under “Appearance”.
7) Based on your observations and results, discuss SOLUBILITY
with your group and fill in the third column of your data table.
8) Clean the test tubes thoroughly with water and a test tube
brush. All materials can be washed down the sink.
9) Put all lab materials back where they belong and clean up your
work area.
SJ #1 Solubility LAB Data Table
1. Write your observations in the table.
Name of Substance Added
to Water
Appearance After
Being Shaken 20
Times
A Copper sulfate
CuSO4
1.
2.
3.
B Sodium chloride
NaCl
1.
2.
3.
C Zinc oxide
ZnO
1.
2.
3.
D Corn starch
C6H10O5
1.
2.
3.
E Powdered sugar
C12H22O11
1.
2.
3.
Does it
Dissolve?
Y or N
1. Which substances are soluble in water? (Write out the names!)
2. What evidence is there that a substance dissolves in water?
List at least 2 observations from the lab.
3. Why were you asked to shake the test tube “vigorously”, instead of
just gently swirling the mixture around?
2. Write your observations of what happens when water is added to the
following:
Substance
Obs Before
a) beach sand
SiO2
1.
2.
b) pink sand
SiO2
1.
2.
c) potassium
permanganate
KMnO4
1.
2.
Trimethylhydroxysilane
C3H10OSi
Prediction w/
water
Obs After