Name _____________
Woodland Park
High School
Chemistry
Unit 9
Solutions
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Name _____________
Chemistry Unit 9: Solutions
Assignment
Can Only be done in Class
Podcast 9.1 Polarity and Solvation
Demo: Bottle Waves
Worksheet 9.1: Polarity and Solvation
Podcast 9.2 Electrolytes and the Nature of
Solutions
Demo: Electrolytes
Worksheet 9.2: Electrolytes and the Nature of
Solutions
Podcast 9.3 Properties of Solutions
Worksheet 9.3: Properties of Solutions
Demo: Solutions—Full Class
Podcast 9.4 Molarity
Worksheet 9.4: Molarity
Podcast 9.5 Dilutions
Lab: Dilution Lab
Podcast 9.6 Colligative Properties
Worksheet 9.6: Colligative Properties
Podcast 9.7: Solution Stoichiometry
Worksheet 9.7: Solution Stoichiometry
Lab: Gravimetric Analysis
Unit 9 Vocab
Unit 9 Exam
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Could be done at home or school
Yes
Yes
Yes
Yes
Done?
Name _____________
Unit 9 Vocab
Dipole
Polar molecule
Van der Waals forces
Dispersion forces
Dipole interactions
Hydrogen bonds
Surface tension
Surfactant
Aqueous solutions
Solvent
Solute
Salvation
Electrolytes
Nonelectrolytes
Weak electrolyte
Strong electrolyte
Efflorsce
Dessicant
Deliquescent
Suspensions
Tyndall effect
Brownian motion
Emulsions
Solubility
Saturated solution
Unsaturated
Miscible
Immiscible
Henry’s Law
Supersaturated solution
Concentration
Dilute solution
Concentrated solution
Molarity
Boiling point elevation
Freezing point depression
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Name _____________
Lab: Bottle Waves—Could be done as a take-home-lab
Subject/Concept: Chemistry - Polar/Nonpolar liquids
Purpose: The purpose of this activity is to observe the effects of combining polar and nonpolar
liquids.
Materials:
• clear bottle with lid (16-20 oz size)
• water
• rubbing alcohol
• food coloring
• vegetable or mineral oil
• duct tape (or other strong tape)
Procedure:
1. Half fill the bottle with water.
2. Add 1/3 cup rubbing alcohol.
3. Add mineral to fill the bottle to the brim.
4. Add 4 drops of food coloring, one at a time.
5. Close the bottle with the lid and seal with tape.
6. Turn the bottle in various directions and observe the waves produced.
Questions:
1. In which liquid did the food coloring dissolve and why?
2. Why do the liquids not mix?
3. Why is the colorless liquid layer always on top?
For Credit:
To receive credit, your parent or guardian must write a short note confirming that you
performed the experiment for them and explained the results to their satisfaction using the
concept of polarity. Attach your note to the back of this sheet.
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Name _____________
Solubility of Gases in a liquid
Solubility of Solids in Liquids
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Name _____________
Take Home Lab
Parent/Student Experiment
Title: Dancing Raisins
Subject/Concepts: Chemistry - Solubility of Gases
Purpose: The purpose of this activity is to observe the buoyant effect of carbonation on raisins.
Materials:
• 2 clear glass cups
•1 cold light colored soda (7-up, Sprite, Ginger Ale, etc)
• 1 warm room light colored soda (room temperature or left in the sun)
NOTE: Sodas must be opened at the start of the experiment and have
plenty of carbonation.
• 20 raisins (approximately)
Procedure:
1. Pour the cold soda in one glass. Pour the warm soda into a second glass.
2. Add 10 raisins to each glass of soda and observe the “dance of the raisins.”
Questions:
1. In which glass do the raisins “dance” faster?
2. Explain your observations using your knowledge of the solubility of gaseous solutes
in liquid solvents at various temperatures.
3. Why do the raisins float up from the bottom of the glass? Why do they sink again
when they reach the top?
For Credit:
To receive credit, your parent or guardian must write a short note confirming that you
performed the experiment for them and explained the results to their satisfaction using the
concept of solubility of gases. Attach your note to the back of this sheet.
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Name _____________
Dilutions Lab
Name
1. Dissolve approximately 2.0 grams of “K2Cr2O7” into either a 250 mL or 200 mL
volumetric flask
2. Determine the molarity of your solution.
3. Using the technique of serial dilutions, make up the following molarities of solutions.
a. 0.00085 M
Show all calculations and put all data in a neat organized table.
You will then transfer your samples into a small test tube. Then take your sample to the teacher
and he or she will test your sample to see if you have the “right” answer.
Procedure:
Sketch a series of pictures that illustrate what you did in this lab
Questions:
1. If your goal is to make a 1.22 x 10-6 M solution why don’t you just make it from the
solid?
2. What would happen to your final molarity if you added too much water to the volumetric
flask in any of the steps? Explain your answer.
3. What would happen to your final molarity if one extra drop of the stock solution is
transferred into the volumetric flask? Explain your answer.
4. We want to make a 0.00034-M solution of sugar-water (C6H12O6). How would you go
about this? You should have a step-by-step procedure and all calculations.
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Name _____________
Gravimetric Analysis Lab: Chemistry
Problem
You are to react approximately 100 mL of 0.15 M calcium chloride with 85 mL or 0.10 M sodium carbonate. The
reaction forms a precipitate, which you will collect via
filtration.
1.
2.
3.
4.
5.
6.
7.
8.
Write the balanced chemical equation for the
reaction above
Determine which product is the precipitate and
label all states of matter in your chemical
equation
Pour both solutions into the flask.
Mass the dry filter paper.
Vacuum filtrate the precipitate. This may take
several successive filtrations to get all of the
precipitate.
Dry all filter papers and record the mass
Subtract out the mass of the filter papers to
determine the mass of the ppt.
While the filtration is going on, perform the
following calculation
 Use the molarities and the volumes to determine the mass of ppt that will form.
Data Table
Volume of calcium chloride
Volume of sodium carbonate
Molarity of calcium chloride
Molarity of sodium carbonate
Mass of filter paper 1
Mass of filter paper 1 after drying with the ppt.
Mass of ppt (from filter paper #1)
Mass of filter paper 2
Mass of filter paper 2 after drying with the ppt.
Mass of ppt (from filter paper #2)
Total mass of the ppt
Expected mass of the ppt (from calculations)
Percent Yield
Procedure
You will need to both explain your procedure and draw pictures that illustrate how you performed this experiment
Calculations
Show all necessary calculations and chemical equations that show how you predicted the amount of ppt that was
formed. Also show the percentage yield for the precipitate.
Questions (answer in complete sentences)
1. Comment on why your percentage yield is not 100%. If the number is greater than 100%, then explain why
it is greater. If the number is less than 100%, then explain why it is less.
2. Give two ways how you could have done this experiment better. (Be very specific)
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Name _____________
Worksheet 9.1: Polarity
1)
Explain why water is polar.
2) Describe the hydrogen bonding between molecules in water
3) How is hydrogen bonding responsible for the high surfaced tension and low vapor
pressure of water?
4) What is a surfactant? How does it affect the surface tension of water?
5) Explain why water has a relatively high boiling point and heat of vaporization.
6) What is the difference between the structure of liquid water and the structure of ice?
How does this explain why ice floats on water?
7) What is the significance of the statement “like dissolves like”? What does “like” refer
to?
8) Which of the following substance dissolve in water? Explain your answer in terms of
polarity.
a. CH4
b. KCl
c. He
d. MgSO4
e. C6H12O6 (glucose—a sugar)
f. NaHCO3
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Name _____________
Worksheet 9.2: Electrolytes-Nature of Solutions
1) Distinguish between electrolyte and a non-electrolyte. Distinguish between a weak
electrolyte and a strong electrolyte. Give an example of each.
2) Identify the solvent and the solute in vinegar, a dilute aqueous solution of acetic acid.
3) Write a chemical equation showing how calcium chloride dissolves in water.
4) What is the basis for distinguishing among solutions, colloids, and suspensions?
5) Give an example of a solution, a colloid, and a suspension.
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Name _____________
Worksheet 9.3: Properties of Solutions
1. Why do the temperatures on
the graph only go from 0º C
to 100º C ?
2. Which substance is most
soluble at 60º C ?
3. Which two substances have
the same solubility at 80º C ?
4. Which substance’s solubility
changes the most from 0º C to
100º C ?
5. Which substance’s solubility
changes the least from 0º C to
100º C ?
6. What is the solubility of
potassium nitrate at 90º C ?
7. At what temperature does potassium iodide have a solubility of 150 g/ 100 cm3 water ?
8. You have a solution of sodium nitrate containing 140 g at 65º C. Is the solution saturated,
unsaturated, or supersaturated ?
9. You have a solution of potassium chlorate containing 4 g at 65º C. How many additional
grams of solute must be added to it, to make the solution saturated ?
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Name _____________
Worksheet 9.4 Molarity
1. Calculate the molarity, M, of the following solutions:
a. 3.0 moles of NaCl are dissolved in 1 liter of solution.
b. 0.5 moles of MgF2 are dissolved in 2 liters of solution.
c. 3 moles of NaOH are dissolved in 0.25 liters of solution.
2. How many liters of a 4.0 M CaCl2 solution would contain 2 moles of CaCl2?
3. How many liters of a 0.5 M CaCl2 solution would contain 3.5 moles of CaCl2?
4. How many liters of a 2.5 M CaCl2 solution would contain 1.0 mole of CaCl2?
5. How many moles of KCl are there in 2 liters of a 3.0 M solution?
6. What is the molarity, M, of a solution in which 116 grams of KF are dissolved in 2 liters
of solution?
7. How many grams of KF are in 2 liters of a 3.0 M solution of KF?
8. How many grams of NH3 are dissolved in 85 mL of a 0.75 M solution?
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Name _____________
Worksheet 9.5 Dilutions
1. 25 mL of 5.6 M HCl are placed in a volumetric flask. The flask is filled to 250 mL with
water. What is the molarity of the new solution?
2. 5.6 mL of NaOH are added to a flask and the flask is filled with water to the 200 mL
mark. The concentration of the new solution is found to be .098 M. What was the initial
molarity of the solution before the dilution was completed?
3. A chemist has 300 mL of a 2.5 M KCl solution. The solution is diluted by adding 1.2 L
of water to the original volume. What is the [KCl] of the diluted solution?
4. A chemist has 2 liters of a 3.2 M hydrochloric acid solution. If the solution is left out in
the room and enough water evaporates so that there is only 1.2 liters of solution left, what
is the final molarity of this concentrated acid?
5. When a chemist adds 1.0 L of water to 3.0 liters of a 0.8 M HF solution, what is the new
concentration of the total HF solution?
6. How much water will a chemist need to add to 200 mL of a 3.3 M KCl solution if they
want to make a 1.0 M solution of KCl?
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Name _____________
Worksheet 9.6: Colligative Properties Worksheet
1. Define each of the following vocabulary terms

colligative property

boiling point elevation

freezing point depression

Molality
2. Explain why the boiling point is elevated and the freezing point is lowered in a solution.
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Name _____________
Worksheet 9.7: Solution Stoichiometry
1) How many grams of AgCl are produced when 40.0 mL of 0.25M AgNO3 is reacted with excess
NaCl? The other product is NaNO3.
2) In the following reaction with excess HCl, 45 mL of 0.100 M NaHCO3 produces how many liters
of carbon dioxide at STP?
NaHCO3 + HCl  NaCl + H2O + CO2
3) Excess Zinc reacts with 1.0 L of 0.50M hydrochloric acid. How many liters of hydrogen gas are
produced at 585 torr and 50°C?
4) 4.50 grams of lead II chromate is produced from the reaction of 100 mL of sodium chromate and
100 mL lead II nitrate. What is the initial molarity of the lead II nitrate?
5) 50.0 mL of 0.75M potassium iodide reacts with 50.0 mL of 0.75 M lead II nitrate. How many
grams of precipitate are formed? (Note that this is both a solution stoichiometry problem and a
limiting reactant problem)
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