Name of
Partner:
Name:
Date
Completed:
Block /
Period:
Date Due:
Teacher:
Mr. Bannister
Exploring Colligative Properties
Introduction / Background: Colligative properties are physical characteristics than can be altered
and manipulated by introducing a solute to the substance. This new solution now will have its
own unique set of physical properties, differing from those exhibited by the parent solvent. The
effect of the addition of the solute on the solvent depends on the quantity solute and the extent of
the dissociated process that takes place.
As the number of particles in solution (i.e. ions or molecules) increases, the amount per volume
of solvent will decrease, creating a lower quantity of liquid molecules able to vaporize and enter
the gaseous phase. This, in turn, will create a lower vapor pressure, one of several examples of a
colligative property. Additional properties include osmotic pressure, boiling point elevation, and
freezing point depression. In freezing point depression, the normal freezing point of a solvent is
decreased by adding a solute, in the case of this lab, a salt, to a sample of water.
Purpose: The purpose of this lab is to experiment with solutions to observe freezing point
depression first hand. Water will normally freeze / melt at 0°C, however this point will decrease
when a solute is added, creating a colder solution. This colder solution will allow the chemicals
to quickly solidify, synthesizing the desired product.
PreLab Questions: Answer the following questions thoroughly prior to the experiment.
1. What determines the extent of the effect the solute will have on the solvent?
2. Would ordinary table sugar have a similar effect as an ionic salt? Why or why not?
EXPLORING COLLIGATIVE PROPERTIES
BANNISTER
3. When considering solutions, what effect does crushing up the solute have on the solubility?
What effect does temperature have? What is the reason behind stirring or shaking a solution?
Define the following terms:
Colligative Property –
Solution –
Solute –
Solvent –
Physical Property –
Vapor Pressure –
Boiling Point Elevation –
Freezing Point Depression –
Osmotic Pressure –
EXPLORING COLLIGATIVE PROPERTIES
BANNISTER
Materials:
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2 Zipping Containment vessels
54.0 grams Cup C6H12O6
100 mL Concentrated Bovine Udder
Secretion
100 mL 2% Bovine Udder Secretion
1 mL Vanilla (use marked pipette)
103.7 grams Cup NaCl or MgCl2
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Thermometer
Solidified, low-entropy H2O
Rolling Barrel
Additional Garnishing (i.e. Cocoa
enriched dairy colloid, ground legume
paste, billowy whipped mammal
secretion, etc.)
Procedure:
1. Combine together 54.0 grams C6H12O6, 100 mL bovine udder secretion, 100 mL
concentrated bovine udder secretion, and 1 mL vanilla to a single zipping containment
vessel, sealing it securely.
2. Fill a rolling barrel about one quarter of the way full with solidified H2O, adding more
when deemed necessary.
3. Use a thermometer to measure and record the temperature of the ice in the rolling barrel.
4. Add approximately 104 grams of NaCl to the barrel of ice. Add increments of 52 grams
when needed.
5. Place the sealed containment vessel inside the rolling barrel with the ice and sodium
chloride. Be sure to replace the cap onto the barrel securely.
6. GENTLY rock the barrel from side to side. It is best to roll the barrel gently as you do
not want to break open the inside vessel nor do you want the salty solution to enter
through.
Caution: Be sure to switch off with partners and / or cover your skin. The resulting
solution will become cold enough to potentially damage your skin.
7. Continue to rock the barrel for 10-15 minutes or until the contents of the internal vessel
have solidified into the desired product.
8. Using a thermometer, record the temperature of the H2O · NaCl solution inside the
rolling barrel.
9. Remove the containment vessel(s) and apply any additional condiments.
Data: **Be sure to keep track and record any additions added along the way
DATA TABLE 1:
Quantity of NaCl used:
(rough estimate)
Temperature of initial
ice solution
Temperature of the
°C
EXPLORING COLLIGATIVE PROPERTIES
NaCl · H2O solution
°C
BANNISTER
Discussions / Conclusions: During phase changes such as what was observed with the ice melting
to form liquid water, energy is either released or absorbed. When energy is absorbed, the sample
will get warmer and increase in temperature. However, energy may be transferred and yet no
temperature increase or decrease is observed. Explain this phenomenon.
What is losing energy? What is gaining energy? Why is this important for the ultimate objective
of this experiment?
What impact did adding more salt have on the physical change’s process? Why? What could be
used to radically decrease the temperature more than what was observed using our salt?
EXPLORING COLLIGATIVE PROPERTIES
BANNISTER