Chapter 8
Molarity
Part 1
Solutions
Solute
• The substance that dissolves (the minor
component of a solution).
KMnO4
Solutions
• Solvent
• The substance that the
solute dissolves in (the
major component of a
solution).
Solution
A homogeneous mixture of the
solute and solvent.
KMnO4 solution
Solutions
Dilute
Concentrated
Concentration of a solution
Molarity(M) is the moles of solute per liter of
solution.
moles of solute
Molarity(M) =
Liters of solution
Common Volume Units
= 1000 mL
Common Volume Units
= 1000 mL
Units of Molarity
Units of Molarity
2.0 M HCl
Units of Molarity
2.0 M HCl
=
2.0 moles HCl
L solution
Units of Molarity
2.0 M HCl
6.0 M HCl
=
2.0 moles HCl
L solution
Units of Molarity
2.0 M HCl
=
2.0 moles HCl
L solution
6.0 M HCl
=
6.0 moles HCl
dm3 solution
Molarity
• Calculate the molarity of an aqueous Ba(NO3)2
solution containing 0.283 grams of barium nitrate
in 0.931 L of solution.
Molarity
• Calculate the molarity of an aqueous Ba(NO3)2
solution containing 0.283 grams of barium nitrate
in 0.931 L of solution.
0.283 g Ba(NO3)2
0.931 L
Molarity
• Calculate the molarity of an aqueous Ba(NO3)2
solution containing 0.283 grams of barium nitrate
in 0.931 L of solution.
0.283 g Ba(NO3)2 mol
0.931 L
261.3 g
Molarity
• Calculate the molarity of an aqueous Ba(NO3)2
solution containing 0.283 grams of barium nitrate
in 0.931 L of solution.
0.283 g Ba(NO3)2 mol
= 0.00116 mol Ba(NO3)2/L
0.931 L
261.3 g
= 0.00116 M Ba(NO3)2
Molarity Calculation
NaOH is used to open stopped sinks, to treat
cellulose in the making of nylon, and to
remove potato peels commercially.
If 4.0 g NaOH are used to make 500.0 mL of NaOH
solution, what is the molarity (M) of the solution?
If 4.0 g NaOH are used to make 500.0 mL of NaOH
solution, what is the molarity (M) of the solution?
4.0 g NaOH
500.0 mL
If 4.0 g NaOH are used to make 500.0 mL of NaOH
solution, what is the molarity (M) of the solution?
4.0 g NaOH mol
500.0 mL
40.0 g
If 4.0 g NaOH are used to make 500.0 mL of NaOH
solution, what is the molarity (M) of the solution?
4.0 g NaOH mol
500.0 mL
mL
40.0 g 0.001 L
If 4.0 g NaOH are used to make 500.0 mL of NaOH
solution, what is the molarity (M) of the solution?
4.0 g NaOH mol
500.0 mL
mL
40.0 g 0.001 L
= 0.20 mol NaOH/L = 0.20M NaOH
Molarity Conversion Factors
An NaOH solution has a molarity of 0.20M.
•
Write this molarity in the form of conversion
factors (ratios).
Molarity Conversion Factors
0.20 moles NaOH and
L solution ____
L solution
0.20 moles NaOH
How many grams of Na2SO4 are required to
prepare 1000.0 mL of 1.0000 M Na2SO4 solution?
How many grams of Na2SO4 are required to
prepare 1000.0 mL of 1.0000 M Na2SO4 solution?
1000.0 mL
How many grams of Na2SO4 are required to
prepare 1000.0 mL of 1.0000 M Na2SO4 solution?
1000.0 mL
0.001 L
mL
How many grams of Na2SO4 are required to
prepare 1000.0 mL of 1.0000 M Na2SO4 solution?
1000.0 mL
0.001 L
mL
1.0000 mol Na2SO4
L
How many grams of Na2SO4 are required to
prepare 1000.0 mL of 1.0000 M Na2SO4 solution?
1000.0 mL
0.001 L
mL
1.0000 mol Na2SO4 142.04 g
L
mol
How many grams of Na2SO4 are required to
prepare 1000.0 mL of 1.0000 M Na2SO4 solution?
1000.0 mL
0.001 L
mL
1.0000 mol Na2SO4 142.04 g
L
mol
= 142.04 g Na2SO4
How to prepare 1000ml (1.000L)
of a 1.0000M solution of Na2SO4.
a
a
Diabetes is a serious medical issue
facing our country at this time.
• 23.6 million people in the United States (7.8% of the total
population) have diabetes. Of these, 5.7 million have
undiagnosed diabetes.
• In 2007, about 1.6 million new cases of diabetes were
diagnosed in people aged 20 years or older.
• If current trends continue, 1 in 3 Americans will develop
diabetes sometime in their lifetime, and those with diabetes will
lose, on average, 10–15 years of life.
• Diabetes is the leading cause of new cases of blindness, kidney
failure, and nontraumatic lower-extremity amputations among
adults.
• Diabetes was the sixth leading cause of death on U.S. death
certificates in 2006. Overall, the risk for death among people
with diabetes is about twice that of people without diabetes of
similar age.
• In 1999–2000, 7% of U.S. adolescents aged 12–19 years had
impaired fasting glucose (prediabetes), putting them at
increased risk of developing type 2 diabetes, heart disease, and
stroke.
Diabetes Is Preventable and
Controllable
• Recent studies show that lifestyle changes can prevent
or delay the onset of type 2 diabetes among people at
high risk.
• For people with prediabetes, lifestyle changes, including
a 5%–7% weight loss and at least 150 minutes of
physical activity per week, can reduce the rate of onset
of type 2 diabetes by 58%.
• Disability and premature death are not inevitable
consequences of diabetes. By working with their support
network and health care providers, people with diabetes
can prevent premature death and disability by controlling
their blood glucose, blood pressure, and blood lipids and
by receiving other preventive care in a timely manner.
Blood sugar is a term referring to the amount of
glucose (C6H12O6) present in the blood. A normal
blood glucose level is about 0.083g in 100.0mL.
What is the molarity of normal blood glucose?
0.0046M C6H12O6
In a college chemistry class you are asked to prepare
100.0 mL solution of 0.250 M NiCl2 (gfm = 129.7g/mol).
In a college chemistry class you are asked to prepare
100.0 mL solution of 0.250 M NiCl2 (gfm = 129.7g/mol).
How do you prepare the solution?
In a college chemistry class you are asked to prepare
100.0 mL solution of 0.250 M NiCl2 (gfm = 129.7g/mol).
How do you prepare the solution.
3.24 grams of NiCl2
Dissolve 3.24 grams of NiCl2 in water then
dilute to a total volume of 100.0 mL.
Information for Mole Quiz
• How does a mole relate to particles and mass? (ie.
One mole of H2O is 6.02 x 1023 H2O molecules and
has a mass of 18.0 g).
• Be able to use the factor-label method to do metric
conversions and mole problems.
• Know how to determine the number of atoms in a
molecule. Be able to use this information in factorlabel problems.
• Be able to determine the number of grams/molecule.
• Identify the diatomic gases.
Homework
 Molarity Worksheet. (Note that the
answers to problem number 2 must be
in sentence form).