General, Organic, and
Biological Chemistry
Fourth Edition
Karen Timberlake
Chapter 8
Solutions
8.5
Dilution of Solutions
and Solution Reactions
© 2013 Pearson Education, Inc.
Lectures
Dilution
In a process called dilution, a solvent, usually water, is
added to a solution increasing its the volume and
decreasing the concentration of the solution.
One can of orange juice concentrate will make four cans of
orange juice.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
2
Dilution
Although the addition of solvent increases the volume,
the amount of solute doesn’t change; it is the same in
the concentrated solution and the diluted solution.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
3
Initial and Diluted Solutions
In the initial and diluted solution,
 the moles of solute are the same, and
 the concentrations and volumes are related by the
following equations:
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Chapter 8, Section 5
4
Guide to Calculating Dilution
Quantities
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
5
Learning Check
What volume of a 2.00% (m/v) HCl solution can be
prepared by diluting 25.0 mL of 14.0% (m/v) HCl solution?
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Chapter 8, Section 5
6
Solution
What volume of a 2.00% (m/v) HCl solution can be
prepared by diluting 25.0 mL of 14.0% (m/v) HCl solution?
Step 1 Prepare a table of the concentrations and
volumes of the solutions.
Analyze the Problem.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
7
Solution
What volume of a 2.00% (m/v) HCl solution can be
prepared by diluting 25.0 mL of 14.0% (m/v) HCl solution?
Step 2 Rearrange the dilution expression to solve for
the unknown quantity.
Step 3 Substitute the known quantities into the
dilution expression and calculate.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
8
Learning Check
What is the molarity (M) of a solution prepared by
diluting 10.0 mL of 2.7 M NaOH to 60.0 mL?
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
9
Solution
What is the molarity (M) of a solution prepared by
diluting 10.0 mL of 2.7 M NaOH to 60.0 mL?
Step 1 Prepare a table of the concentrations and
volumes of the solutions.
Analyze the Problem.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
10
Solution
What is the molarity (M) of a solution prepared by
diluting 10.0 mL of 2.7 M NaOH to 60.0 mL?
Step 2 Rearrange the dilution expression to solve
for the unknown quantity.
Step 3 Substitute the known quantities into the
dilution expression and calculate.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
11
Solutions in Chemical Reactions
When chemical reactions involve aqueous solutions, we
use molarity and volume to determine the moles of the
substances required or produced.
Zinc reacts with HCl to produce ZnCl2 and hydrogen gas H2.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
12
Guide to Calculations Involving
Solutions in Chemical Reactions
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Chapter 8, Section 5
13
Learning Check
How many liters of 3.00 M HCl are needed to completely
react with 4.85 g of CaCO3?
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Chapter 8, Section 5
14
Solution
How many liters of 3.00 M HCl are needed to completely
react with 4.85 g of CaCO3?
Step 1 State the given and needed quantities.
Analyze the Problem.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
15
Solution
How many liters of 3.00 M HCl are needed to completely
react with 4.85 g of CaCO3?
Step 2 Write a plan to calculate the needed quantity
or concentration.
mass
molar moles mole–mole moles molarity liters
of CaCO3 mass of CaCO3 factor
of HCl HCl
of HCl
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
16
Solution
How many liters of 3.00 M HCl are needed to completely
react with 4.85 g of CaCO3?
Step 3 Write equalities and conversion factors
including mole–mole and concentration.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
17
Solution
How many liters of 3.00 M HCl are needed to completely
react with 4.85 g of CaCO3?
Step 3 Write equalities and conversion factors
including mole–mole and concentration.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
18
Solution
How many liters of 3.00 M HCl are needed to completely
react with 4.85 g of CaCO3?
Step 4 Set up the problem to calculate the needed
quantity or concentration.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
19
Learning Check
If 22 mL of 0.10 M MgCl2 is needed to completely react
15 mL of AgNO3 solution, what is the molarity of AgNO3?
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
20
Solution
If 22 mL of 0.10 M MgCl2 is needed to completely react
15 mL of AgNO3 solution, what is the molarity of AgNO3?
Step 1 State the given and needed quantities.
Analyze the Problem.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
21
Solution
If 22 mL of 0.10 M MgCl2 is needed to completely react
15 mL of AgNO3 solution, what is the molarity of AgNO3?
Step 2 Write a plan to calculate the needed quantity
or concentration.
volume molarity moles mole–mole
of MgCl2 MgCl2 of MgCl2 factor
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Chapter 8, Section 5
moles
of AgNO3
22
Solution
If 22 mL of 0.10 M MgCl2 is needed to completely react
15 mL of AgNO3 solution, what is the molarity of AgNO3?
Step 3 Write equalities and conversion factors
including mole–mole and concentration.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
23
Solution
If 22 mL of 0.10 M MgCl2 is needed to completely react
15 mL of AgNO3 solution, what is the molarity of AgNO3?
Step 4 Set up the problem to calculate the needed
quantity or concentration.
© 2013 Pearson Education, Inc.
Chapter 8, Section 5
24