CH 104: SOLUBILITY AND SOLUTIONS • In today’s experiment you will measure the molarity (M), molality (m), mole fraction (χ), and mass.
Download ReportTranscript CH 104: SOLUBILITY AND SOLUTIONS • In today’s experiment you will measure the molarity (M), molality (m), mole fraction (χ), and mass.
Slide 1
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 2
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 3
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 4
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 5
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 6
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 7
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 8
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 9
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 2
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 3
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 4
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 5
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 6
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 7
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 8
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].
Slide 9
CH 104: SOLUBILITY AND SOLUTIONS
• In today’s experiment you will measure the molarity (M), molality (m),
mole fraction (χ), and mass percent of a potassium chloride (KCl)
solution.
• What is molarity (M)?
• What is molality (m)?
• What is mole fraction (χ)?
• What is mass percent?
• Which, if any, of these concentrations will change with temperature?
• Only molarity (M) will change with temperature. The volume of solution
changes with temperature. In contrast, the moles of solute, mass of
solute, moles of solvent, and mass of solvent do not change with
temperature.
SOLUBILITY AND SOLUTIONS
• A solution is made by dissolving 1.370 grams (g) of KCl in
100.0 g of water. Its final volume is 100.9 milliliters (mL).
What are the molarity (M), molality (m), mole fraction of KCl
(χKCl), and mass percent of KCl for this solution?
You just calculated 4
different concentrations
of KCl for the same
solution. Each has its
advantages and
disadvantages.
SOLUBILITY AND SOLUTIONS
• The terms insoluble, slightly soluble, soluble, and very
soluble describe the relative solubility of a substance in a
solvent.
• In today’s experiment you will use these terms to compare
the solubilities of sodium carbonate (Na2CO3), naphthalene
(C10H8), and calcium carbonate (CaCO3) in 2 different
solvents.
• The first solvent is water (H2O) and the second solvent is
cyclohexane (C6H12). Water is relatively polar and C6H12 is
relatively nonpolar.
• “Like dissolves like.” That is, polar solvents tend to
dissolve polar solutes. And nonpolar solvents tend to
dissolve nonpolar solutes.
SOLUBILITY AND SOLUTIONS
• Describe the electrostatics for the dissolution of an ionic crystal in
water.
• Water dipoles cluster around ions at the surface of the crystal. The
negative ends of these dipoles are oriented toward the positive ions
(cations). In contrast, the positive ends of these dipoles are oriented
toward the negative ions (anions). The solid will dissolve if these iondipole forces are greater than the interionic attractions within the
crystal. Moreover, these ion-dipole forces persist in the solution. An
ion is hydrated when it is surrounded by water molecules.
SOLUBILITY AND SOLUTIONS
• The terms immiscible, partially miscible, and infinitely miscible
describe the relative solubility of a liquid solute in a liquid solvent.
• In today’s experiment you will use these terms to compare the
miscibility of water (H2O), 2-propanol (isopropyl alcohol,
CH3CHOHCH3), and cyclohexane (C6H12). Water is the most polar and
C6H12 is the least polar. Why?
• Water has 2 hydrogens bonded to oxygen. CH3CHOHCH3 has 1
hydrogen bonded to oxygen. And C6H12 has no hydrogens bonded to
oxygen. These OH groups are polar and form hydrogen bonds with
other molecules.
The hydrogen bonds of water are shown as dotted lines.
SOLUBILITY AND SOLUTIONS
• A corollary to “like dissolves like” is “oil and water don’t
mix”.
Oil and water in a separatory funnel.
SOLUBILITY AND SOLUTIONS
• Why doesn’t oil and water mix?
The hydrogen bonds of water are shown as dotted lines.
• Water is an associated liquid; that is, adjacent water molecules are held
together by relatively strong hydrogen bonds. In contrast, oils and
other nonpolar liquid are held together by relatively weak
intermolecular forces. Therefore, the attraction between oil and water
molecules is not strong enough for the oil to break the hydrogen bonds
of water and dissolve into the water.
SAFETY
• Do NOT use cyclohexane (C6H12) or 2-propanol
(CH3CHOHCH3) until all the Bunsen burners in the
laboratory are extinguished. Treat these compounds as if
they were gasoline. They are extremely flammable.
• Wear your goggles at all times.
• Your laboratory manual has an extensive list of safety
procedures. Read and understand this section.
• Ask your instructor if you ever have any questions about
safety.
SOURCES
• McMurry, J., R.C. Fay. 2004. Chemistry, 4th ed. Upper
Saddle River, NJ: Prentice Hall.
• Petrucci, R.H. 1985. General Chemistry Principles and
Modern Applications, 4th ed. New York, NY: Macmillan
Publishing Company.
• Wright, A.E. 2006. NOAA Ocean Explorer. Available:
http://www.oceanexplorer.noaa.gov/explorations/02sab/bac
kground/products/products.html [accessed 13 December
2006].