1
Solutions Vocabulary
1.
2.
3.
4.
5.
6.
Saturated solution
Solubility
Unsaturated solution
Miscible
Immiscible
Supersaturated
solution
7. Concentration
8. Diluted solution
9. Molarity
10.
11.
12.
13.
14.
15.
Colligative property
Freezing-point depression
Concentrated solution
Boiling-point elevation
Molality
Molar freezing-point
depression constant (Kf)
16. Molar boiling-point
elevation constant (Kb)
Matter Flowchart
MATTER
yes
MIXTURE
yes
Is the composition
uniform?
Homogeneous
Mixture
(solution)
PURE SUBSTANCE
no
Heterogeneous
Mixture
Colloids
no
Can it be physically
separated?
yes
Can it be chemically
decomposed?
Compound
Suspensions
no
Element
Homogeneous Mixture (Solution)
•
•
•
•
Same throughout
Small particles
Dissolved
Can be solid, liquid, or gas
Parts of a Solution
Solute - substance
being dissolved
Solvent - present in
greater amount
What are some examples of homogeneous
mixtures?
Solute
Solvent
Example
solid
solid
Alloys (brass, steel)
solid
liquid
Salt water
gas
solid
Air bubbles in ice cubes
liquid
liquid
Rubbing alcohol, vinegar
gas
liquid
Soda
gas
gas
Air
Unsaturated vs. Saturated
Supersaturated Solutions
• Contains more solute than a
saturated solution
How to Increase Solubility:
–Add more solvent
–Heat
–Stir
–Broken solute into smaller
particles
Concentration of
Solute:
Molarity
13
The amount of solute in a solution is
given by its concentration.
Molarity (M) =
moles solute
liters of solution
*to convert mass to moles:
Reasoning: Many
solutions are made up of
the same substances, but
in varying concentrations.
mass x
1 mol
1
molar mass
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Molarity Lab
Lemonade
Anyone?
15
Qualitative Data
Bottle
A
B
C
Concentration Rank (1-strongest; 3-weakest)
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Quantitative Data
Bottle
Liters of
Solution
Grams
of Mix
A
1.89
160
B
1.89
46
C
1.89
90
Grams of
Sucrose
*Moles
grams
of
of Citric
Sucrose
Acid
M=
*Moles
of Citric
Acid
mol mix
a
Liters of solution
Moles
of Mix
Molarity
of Mix
*to convert mass to moles:
Sucrose—C12H22O11
Citric Acid—C6H8O7
Assume the mix is
half sucrose and
half citric acid
mass x
1 mol
1
molar mass
17
A 4.0 g sugar cube (sucrose: C12H22O11) is
dissolved in a 350 ml teacup filled with hot water.
What is the molarity of the sugar solution?
• Step 1: Make all of the needed conversions.
– Convert grams to moles.
– Convert mL to L.
• Step 2: Calculate Molarity
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Electrolyte Simulation Lab
• http://phet.colorado.edu/en/simulation/sugarand-salt-solutions
19
PHET Lab
1. How much salt (in grams) is in the salt
shaker?
2. How much sugar (in grams) is in the sugar
shaker?
3. Why does the light bulb light up in the
_________ solution but not the _________
solution?
4. What is an electrolyte?
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Colligative Properties
Properties that change as concentration
of a solution changes
•
•
•
•
Density, color, taste
Vapor pressure
Boiling point
Freezing point
http://www.gpb.org/chemistry-physics/chemistry/1003
Colligative Property:
Density & Color
Taste
Vapor Pressure Depression
Freezing Point Depression
Boiling Point Elevation
Picture:
Explanation:
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22
Density & Color
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Taste
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Electrolytes vs. Nonelectrolytes
The magnitude of the colligative
property is directly proportional to
the number of solute molecules or
ions present.
More of an
effect on the
colligative
properties.
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Vapor Pressure Depression
3,5
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Boiling Point Elevation
4,7
• Because vapor
pressure is
lowered, a
higher
temperature is
required to
push the
molecules
from liquid to
gas state.
Freezing Point Depression
6,8
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Work Session
• Colligative Properties
Concept Review
Solutions Test
• Vocabulary
• Solubility Curve
• Colligative Properties
• Molarity Calculations