Holt Modern Chemistry Review
CHAPTER 12 & 13: SOLUTIONS
The following pages contain the bulk (but not all) of the information for the chapter 12 & 13 test.
Focus on this content, but make sure to review class notes, activities, handouts, questions, etc.
If you study this document and NOTHING else, you should at least be able to PASS the test.
***** Test items will be recall, examples, and/or application of this content. *****
OUTCOMES
 Collaborate with peer(s) to understand chemistry content (C C)
 Communicate chemistry content to teacher and peer(s) (E C)
 12.1: Distinguish between an electrolyte and non-electrolyte solution and know examples (T & R)
 12.2: Explain the effect of temperature on solubility (graph on wkbk pg. 392 & textbook pg. 414) (T & R)
 12.3: Know types of concentration and be able to solve molarity and molality problems (F & PK)
 13.2: Explain freezing point depression and boiling point elevation (T & R)
12.1: TYPES OF MIXTURES
 Vocabulary
o solution -- a homogeneous mixture of two or more substances uniformly dispersed throughout a single phase.
o suspension -- a mixture in which particles of a material are more or less evenly dispersed throughout a liquid or gas.
o colloid -- a mixture consisting of tiny particles that are intermediate in size between those in solutions and those in suspensions and that are
suspended in a liquid, solid, or gas.
o soluble -- capable of dissolving in a particular solvent.
o solvent -- in a solution, the substance in which the solute dissolves.
o solute -- in a solution, the substance that dissolves in the solvent.
o electrolyte -- a substance that dissolves in water to give a solution that conducts an electric current.
o nonelectrolyte -- a liquid or solid substance or mixture that does not allow an electric current.
 Chapter Highlights
o Solutions are homogeneous mixtures.
o Mixtures are classified as solutions, suspensions, or colloids, depending on the size of the solute particles in the mixture.
o The dissolved substance is the solute. Solutions that have water as a solvent are aqueous solutions.
o Solutions can consist of solutes and solvents that are solids, liquids, or gases.
o Suspensions settle out upon standing. Colloids do not settle out, and they scatter light that is shined through them.
o Most ionic solutes and some molecular solutes form aqueous solutions that conduct an electric current. (Heart failure is a hazard of electrical
energy.) These solutes are called electrolytes.
electrolyte = ionic (metal + nonmetal) bond
Ex. NaCl, LiF
o Nonelectrolytes are solutes that dissolve in water to form solutions that do not conduct
 nonelectrolyte = covalent (nonmetal + nonmetal) bond
Ex. CO2
12.2: THE SOLUTION PROCESS
 Vocabulary
o saturated solution -- a solution that cannot dissolve any more solute under the given conditions.
o unsaturated solution -- a solution that contains less solute than a saturated solution does and that is able to dissolve additional solute.
o supersaturated solution -- a solution that holds more dissolved solute than is required to reach equilibrium at a given temperature.
o solubility -- the ability of one substance to dissolve in another at a given temperature and pressure; expressed in terms of the amount of solute
that will dissolve in a given amount of solvent to produce a saturated solution.
o immiscible -- describes two or more liquids that do not mix with each other.
o miscible -- describes two or more liquids that can dissolve into each other in various proportions.
o effervescence -- a bubbling of a liquid caused by the rapid escape of a gas rather than by boiling.
o enthalpy of solution -- the amount of energy released or absorbed as heat when a specific amount of solute dissolves in a solvent.
 Chapter Highlights
o A solute dissolves at a rate that depends on the surface area of the solute, how vigorously the solution is mixed, and the temperature of the
solvent.
o The solubility of a substance indicates how much of that substance will dissolve in a specified amount of solvent under certain conditions.
o The solubility of a substance depends on the temperature.
o The solubility of gases in liquids increases with increases in pressure.
o The solubility of gases in liquids decreases with increases in temperature.
o The overall energy absorbed as heat by the system when a specified amount of solute dissolved during solution formation is called the enthalpy of
solution.
12.3: CONCENTRATION OF SOLUTIONS
 Vocabulary
o concentration -- the amount of a particular substance in a given quantity of a mixture, solution, or ore.
o molarity -- a concentration unit of a solution expressed as moles of solute dissolved per liter of solution; M = moles of solute / L of solution
 Chapter Highlights
o The molar concentration of a solution represents the ratio of moles of solute to liters of solution.
o Molality is the concentration of a solution expressed in moles of solute per kilogram of solvent. Both molarity and molality are measures of the
concentration of a substance.
13.1: COMPOUNDS IN AQUEOUS SOLUTION
 Vocabulary
o dissociation -- the separating of a molecule into simpler molecules, atoms, radicals, or ions
o net ionic equation -- an equation that includes only those compounds and ions that undergo a chemical change in a reaction in an aqueous
solution
o ionization -- the process of adding or removing electrons from an atom or molecule, which gives the atom or molecule a net charge
 Chapter Highlights
o The separation of ions that occurs when an ionic solid dissolves is called dissociation.
o A net ionic equation for a reaction in aqueous solution includes only compounds and ions that change chemically in the reaction. Spectator ions
are ions that do not take part in such a reaction.
o Formation of ions from molecular compounds is called ionization. A molecular compound may ionize in an aqueous solution if the attraction of the
polar water molecules is strong enough to break the polar-covalent bonds of the solute molecules.
13.2: COLLIGATIVE PROPERTIES OF SOLUTIONS
 Vocabulary
o freezing-point depression -- the difference between the freezing points of a pure solvent and a solution, which is directly proportional to the
amount of solute present
o boiling-point elevation -- the difference between the boiling point of a liquid in pure state and the boiling point of the liquid in solution; the
increase depends on the amount of solute particles present
o semipermeable membrane -- a membrane that permits the passage of only certain molecules
o osmosis -- the diffusion of water or another solvent from a more dilute solution (of a solute) to a more concentrated solution (of the solute)
through a membrane that is permeable to the solvent
 Chapter Highlights
o When a solid solute is added to a liquid solvent the boiling point is elevated (raised), and the freezing point is depressed (lowered).
o The molal boiling-point and freezing-point constants are used to calculate boiling-point elevations and freezing-point depressions of solvents
containing nonvolatile solutes.
o Electrolytes have a greater effect on the freezing and boiling points of solvents than nonelectrolytes do.
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EXAMPLE PROBLEM #1:
EXAMPLE PROBLEM #2:
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SOLUBILITY CURVES:
 On the graph at right, which substance is LEAST affected by
temperature?
ANSWER: NaCl
 On the graph at right, which substance is MOST affected by
temperature?
ANSWER: KNO3
 How many grams of NaNO3 at 20oC does it take to make a
saturated solution?
ANSWER: 88g
12.2
1. solution equilibrium -- the physical state in which the opposing processes of dissolution and crystallization of a solute occur at equal rates.
2. hydration -- the strong affinity of water molecules for particles of dissolved or suspended substances that causes electrolytic dissociation.
3. Henry’s law -- the law that states that at constant temperature, the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas
on the surface of the liquid.
4. solvated -- describes a solute molecule that is surrounded by solvent molecules.
12.3
molality -- the concentration of a solution expressed in moles of solute per kilogram of solvent.
13.1
spectator ion
hydronium ion
strong electrolyte
weak electrolyte
13.2
colligative properties
nonvolatile substance
molal freezing-point constant
molal boiling-point constant
osmotic pressure