Name: ________________________
Date: _________________________
Period: _______
Regents Chemistry
Teacher Name : _____________
Pre Activity Questions:
1. How do sodium chloride and Ammonia (NH3) differ in the way that they bond?
_________________________________________________________________________________________
________________________________________________________________________________________.
2. Sketch a particle diagram of both sodium chloride and ammonia dissolved in water (include dipoles) and
(include at least 2 particles of each!):
Ammonia
Sodium Chloride
3. Explain (using concepts discussed in class) what must occur for a liquid to boil.
_________________________________________________________________________________________
_________________________________________________________________________________________
________________________________________________________________________________________.
4. Define freezing point and boiling point (and give the freezing point and boiling point of pure water).
a. Freezing point: ________ °C
i. ____________________________________________________________________________
___________________________________________________________________________.
b. Boiling point: ________ °C
i. ____________________________________________________________________________
___________________________________________________________________________.
5. Hypothesize which compound will have a greater effect on the boiling point of the solution (if, then,
because):_________________________________________________________________________________
_________________________________________________________________________________________
________________________________________________________________________________________.
Name: ________________________
Date: _________________________
Period: _______
Regents Chemistry
Teacher Name : _____________
Activity: With your partner follow the instructions below to complete the activity.
Log in to your computer and go to the following website.
Freezing Point Activity:
For Activity #1, choose the following options: cold bath (click on the switch), and 100g of distilled H2O, click start.
Record your data in the table.
For Activity #2, choose cold water bath, 100g H2O, and 2.0g of Sodium Chloride (NaCl), click start. Record your data.
For Activity #3, choose cold water bath, 100 g H2O, and 4.0g of Sodium Chloride (NaCl), click start. Record your data.
Experiment
Freezing point
Δ T (freezing point of water –
freezing point of solution)
1 – pure H2O
2- H2O & 2.0 g NaCl
3- H2O & 4.0 g NaCl
Freezing Point Questions:
1. What happened to the freezing point of the pure water when you added a solute?
_____.
2. Why did this occur?
_____.
3. When you doubled the amount of solute, what effect did this have on the change in freezing point?
______.
4. Calculate the number of moles of solute particles added to experiments 1-3.
SHOW YOUR WORK.
Experiment 1
Experiment 2
Experiment 3
Name: ________________________
Date: _________________________
Period: _______
Regents Chemistry
Teacher Name : _____________
For Activity #4, choose the following options: cold bath (click on the switch), and 100g of distilled H2O, click start.
Record your data in the table.
For Activity #5, choose cold water bath, 100g H2O, and 2.0g of Sucrose (C12H22O11), click start. Record your data.
For Activity #6, choose cold water bath, 100 g H2O, and 4.0g of Sucrose (C12H22O11) click start. Record your data.
Experiment
Freezing point
Δ T (freezing point of water –
freezing point of solution)
4 – pure H2O
5- H2O & 2.0 g C12H22O11
6- H2O & 4.0 g C12H22O11
Freezing Point Questions:
1. What happened to the freezing point of the pure water when you added a solute?
_____.
2. Why did this occur?
_____.
3. When you doubled the amount of solute, what effect did this have on the change in freezing point?
_____.
4. Calculate the number of moles of solute particles added to experiments 1-3.
SHOW YOUR WORK.
Experiment 1
Experiment 2
Experiment 3
Name: ________________________
Date: _________________________
Period: _______
Regents Chemistry
Teacher Name : _____________
Boiling Point:
For Experiment #1:
1. Choose a hot water bath, 100g of distilled H2O. Record the boiling point under NaCl.
2. Choose a hot water bath, 100g of distilled H2O. Record the boiling point under C11H22O11.
For Experiment #2:
1. Choose a hot water bath, 100g of H2O, and 2.0g of NaCl. Record the boiling point.
2. Choose a hot water bath, 100g of H2O, and 2.0g of C11H22O11. Record the boiling point.
For Experiment #3:
1. Choose a hot water bath, 100g of H2O, and 4.0g of NaCl. Record the temperature.
2. Choose a hot water bath, 100g of H2O, and 4.0g of C11H22O11. Record the temperature.
Boiling Point (°C)
Experiment
NaCl
C11H22O11
1- pure H2O
2- H2O and 2.0 g of solute
3- H2O and 4.0 g of solute
Boiling Point Questions:
1. What happened to the boiling point of the pure water when you added a solute? Explain
______.
2. When you doubled the amount of solute, what effect did this have on the change in boiling point?
3.
______.
Which had a larger impact on the boiling point change: NaCl or C11H22O11? Explain. _____________________
_________________________________________________________________________________________
_________________________________________________________________________________________
________________________________________________________________________________________.
Summary Questions:
1. Why is calcium chloride used on sidewalks and roads during the winter instead of sodium chloride? Explain in
terms of colligative properties. _______________________________________________________________
_________________________________________________________________________________________
________________________________________________________________________________________.
2. A 2.50-L aqueous solution contains 1.25 moles of dissolved sodium chloride. The dissolving of NaCl(s) in H2O is
represented by the equation below:
NaCl(s)  Na+(aq) + Cl-(aq)
Compare the freezing point of this solution to the freezing point of a solution containing 0.75 moles NaCl per
2.50-L of solution. Explain. ___________________________________________________________________
_________________________________________________________________________________________
________________________________________________________________________________________.