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Period ______
CRHS Academic Chemistry
UNIT 12 Solutions
Homework
Due Date
Assignment
On-Time (100)
Late (70)
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12.1
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12.2
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12.3
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12.4
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Warm-Up
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EC
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Notes, Homework, Exam Reviews and Their KEYS located on CRHS Academic Chemistry
Website: https://cincochem.pbworks.com
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WARM-UPS
Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Unit 12 HW
Unit 12 HW
Extra Credit
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Unit 12 HW
12.1 WATER AND TYPES OF SOLUTIONS
1. Water is a polar molecule. What does “polar” mean?
2. Water molecules are held together by ( STRONG / WEAK ) hydrogen bonds.
3. Why does water have a relatively high boiling point?
4. Solid water (ice) takes on a 3 dimensional shape that contains much more empty space than water.

How does this explain why ice floats in water?
5. What does “like dissolves like” mean?
6. What is a solution?
7. What is an aqueous solution?
8. To make chocolate milk, you stir 2 spoons of chocolate syrup into 2 cups of milk. CIRCLE the solvent and BOX the
solute.
Unit 12 HW
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9. For each action, write whether it would increase (I), decrease (D), or have no effect (N), on the solubility of the solid
solute.
a. Decreasing the temperature of the solution ________
b. Decreasing the pressure over the solution ________
c. Adding a nonpolar solute to a polar solvent ________
10. For each action, write whether it would increase (I), decrease (D), or have no effect (N), on the solubility of the
gaseous solute.
a. Placing a soda in the refrigerator ________
b. Increasing the temperature of the solution _______
c. Decreasing the pressure around the solution _______
11. For each action, write whether it would increase (I), decrease (D), or have no effect (N), on the RATE of solubility of
the solute.
a. Using a packet of sugar instead of a sugar cube _______
b. Heating up a sugar and tea solution _______
c. Stirring a solid solute into a solution of water_______
12. Circle the below compounds that are electrolytes.
CCl4
SF6
NaCl
BaO
13. List two pairs of liquids that YOU know of that are miscible.
14. List two pairs of liquids that are immiscible.
PH3
K2SO4
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Unit 12 HW
12.2 SOLUBILITY GRAPHS AND CURVES
Temperature - Solubility Relationships
200
Solubility, grams of solute per 100 grams of water
KNO3
NaNO3
180
CsCl
NaC2H3O2
160
RbCl
140
LiCl
120
100
KI
CuSO4
80
NH4Cl
60
KCl
40
NaCl
20
0
0
20
40
60
80
100
Temperature (°C)
Use the graph to answer all questions.
1. How much KNO3 dissolves in 100 g of water that is 30 C? ________
2. How much KNO3 dissolves in 100 g of water that is 70 C? ________
3. How many grams of KCl will dissolve in 200 g of water at 45 C? _________
4. How many grams of NaNO3 are required to make a saturated solution in 100.0 g of water at 70 C?________
5. How much NH4Cl will dissolve in 50.0 grams of water at 70 C? __________
6. At what temperature will a saturated solution of SO2 hold 20 grams of solute? __________
7. As the temperature of the solution increases, the solubility of LiCl
( INCREASES / DECREASES ).
8. The solubility of KI ( INCREASES / DECREASES ) with a decrease in temperature.
Unit 12 HW
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9. Circle the correct description of each solution.
a. 50.0 g of KCl in 100.0 g of water at 80 C
( Unsaturated / Saturated / Supersaturated )
b. 135 g of KI in 100.0 g of water at 90 C
( Unsaturated / Saturated / Supersaturated )
c. 40.0 g of NaNO3 in 50.0 g of water at 10 C
( Unsaturated / Saturated / Supersaturated )
d. 26.0 g of NaCl in 100.0 g of water at 80 C
( Unsaturated / Saturated / Supersaturated )
10. 150 grams of NaNO3 are in 100 mL of water at 40.0 C. If more NaNO3 is added, will it dissolve? ( YES / NO )
11. At what temperature is the solubility of NaNO3 equal to the solubility of KNO3? ___________
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Unit 12 HW
12.3 MOLARITY AND DILUTIONS
1. 25.0 grams of CsCl is placed in 100.0 grams of water at 25.0 C. Will all of the CsCl dissolve? ( YES / NO )
2. What is the molarity of 1.5 L of solution that contains 0.50 mol MgCl2?
3. What is the molarity of 250 mL of solution that contains 0.70 mol NaCl?
4. How many moles of solute are present in 1.5 L of 0.24 M Na2SO4?
5. How many grams of CaCl2 are in 250 mL of 2.0 M CaCl2 solution?
6. What is the molarity of a solution made by dissolving 80.0 grams of NaOH in one liter of solution?
Unit 12 HW
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7. If I have 0.60 moles of sodium iodide how much water would it take to make a 0.25 M solution?
8. How many mL of initial solution of 2.00 M MgSO4 would you need to prepare 100.0 mL of 0.400 M MgSO4?
9. If you need 250 mL of 0.20 M NaCl, what volume of a 1.0 M NaCl, solution do you need?
10. You dilute 50.0 mL of 5.0 M NaCl to make a 500.0 mL of solution, what is the molarity of the dilute solution?
11. How many liters of 15 M sodium nitrate are needed make 225 mL of a 0.100 M solution?
12. If you had 43.0 mL of a 3.00 M hydrochloric acid solution and you dilute it to 500 mL, what is the new molarity?
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Unit 12 HW
12.4 COLLIGATIVE PROPERTIES
1.
Why does a solution have a lower vapor pressure than the pure solvent of that solution?
2.
Would a dilute or a concentrated sodium fluoride solution have a higher boiling point? Explain.
3.
Would the freezing point of 0.5 mol NaCl in 100 mL water be higher or lower than 0 C? Explain.
4.
An aqueous solution freezes at –2.47 C. Will this solution’s boiling point be greater than, the same as, or less
than 100 C.
5.
Why would calcium chloride (CaCl2) spread on icy roads be more effective at melting ice than sodium chloride
(NaCl)?
6.
Compared to pure water, an aqueous solution of potassium bromide has a ___________ boiling point,
_______________ freezing point, and a __________________ vapor pressure. (Insert higher or lower into each blank.)
Unit 12 HW
7.
What properties do solutions and colloids have in common?
8.
What properties do solutions and suspensions have in common?
9.
What properties do colloids and suspensions have in common?
10.
What is the Tyndall effect?
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Unit 12 HW