M.Elizabeth Chemistry 2010-2011
Spring Semester January 24 - February 7
Solutions Chapter 15 in textbook
- GUHS Solution SG word
- Solutions ppt notes
- Vocabulary Sheet word
- Bellringers word
- Chapter 15 Study Guide pdf
- Solutions Overview Notes word
- Solutions Review Questions word
- Background Lessons Molarity pdf Percent Solutions pdf Dilutions pdf
Annenberg Film Series States of Matter Questions word
Kinetic Molecular Theory - Phase Diagrams Intro with specific heat Intro word Phase Diagrams Practice pdf
Introduction to solutions movie notes lab and practice
Solutions movie notes practice/lab
Molarity and Colligative Properties movie notes lab molarity practice colligative practice
Solutions Review pdf
>> Molarity Practice Problems word
>> Solubility Curve Interpretation word Practice 2 pdf Practice 3 word
>> Practice Problems with solutions word
>> Solution Concentration Problems pdf
Online Resources (Web Sites)
- Virtual Lab Kinetic Molecular Theory link
- Molarity ChemTour Dilutions ChemTour Migration of Ions ChemTour Saturated Solutions ChemTour
- Solutions with Canadian Connections link
Chapter 15 contains the following units:
What are solutions?
Colligative Properties and Solutions
- Solutions are homogeneous mixtures of two or more substances. As a basis for understanding this concept:
- Students know the definitions of solute and solvent.
- Students know how to describe the dissolving process at the molecular level by using the concept of random
- Students know temperature, pressure, and surface area affect the dissolving process.
- Students know how to calculate the concentration of a solute in terms of grams per liter, molarity, parts per
million, and percent composition.
California Science Standard - Chemistry
6. Solutions are homogeneous mixtures of two or more substances. As a basis for understanding this concept:
a. Students know the definitions of solute and solvent.
Simple solutions are homogeneous mixtures of two substances. A solute is the dissolved substance in a solution, and a solvent is, by
quantity, the major component in the solution.
6. b. Students know how to describe the dissolving process at the molecular level by using the concept of random molecular motion.
The kinetic molecular theory as applied to gases can be extended to explain how the solute and solvent particles are in
constant random motion. The kinetic energy of this motion causes diffusion of the solute into the solvent, resulting in a
homogeneous solution. When a solid is in contact with a liquid, at least some small degree of dissolution always occurs. The
equilibrium concentration of solute in solvent will depend on the surface interactions between the molecules of solute and
solvent. Equilibrium is reached when all competing processes are in balance. Those processes include the tendency for
dissolved molecules to spread randomly in the solvent and the competing strength of the bonds and other forces among
solute molecules, among solvent molecules, and between solute and solvent molecules. When salts dissolve in water, positive
and negative ions are separated and surrounded by polar water molecules.
6. c. Students know temperature, pressure, and surface area affect the dissolving process.
In a liquid solvent, solubility of gases and solids is a function of temperature. Students should have experience with
reactions in which precipitates are formed or gases are released from solution, and they should be taught that the
concentration of a substance that appears as solid or gas must exceed the solubility of the solvent.
Increasing the temperature usually increases the solubility of solid solutes but always decreases the solubility of gaseous
solutes. An example of a solid ionic solute compound that decreases in solubility as the temperature increases is Na2SO4.
An example of one that increases in solubility as the temperature increases is NaNO3. The solubility of a gas in a liquid is
directly proportional to the pressure of that gas above the solution. It is important to distinguish solubility equilibrium from
rates of dissolution. Concepts of equilibrium describe only how much solute will dissolve at equilibrium, not how quickly this
process will occur.
6. d. Students know how to calculate the concentration of a solute in terms of grams per liter, molarity, parts per million, and
All concentration units listed previously are a measure of the amount of solute compared with the amount of solution. Grams 6. e.* Students know the relationship between the molality of a solute in a solution and the solution’s depressed freezing point or
per liter represent the mass of solute divided by the volume of solution. Molarity describes moles of solute divided by
liters of solution. Students can calculate the number of moles of dissolved solute and divide by the volume in liters of the
total solution, yielding units of moles per liter. Parts per million, which is a ratio of one part of solute to one million parts of
solvent, is usually applied to very dilute solutions. Percent composition is the ratio of one part of solvent to one hundred
parts of solvent and is expressed as a percent. To calculate parts per million and percent composition, students determine
the mass of solvent and solute and then divide the mass of the solute by the total mass of the solution. This number is then
multiplied by 106 and expressed as parts per million (ppm) or by 100 and expressed as a percent.
elevated boiling point.
The physical properties of the freezing point and boiling point of a solution are directly proportional to the concentration of 6. f.* Students know how molecules in a solution are separated or purified by the methods of chromatography and distillation.
the solution in molality. Molality is similar to molarity except that molality expresses moles of solute dissolved in a kilogram
of solvent rather than in a liter of solution. In other words, molality is the amount of solute present divided by the amount
of solvent present. Molality is a convenient measure because it does not depend on volume and therefore does not change
with temperature. Sometimes physical properties change with concentration of solute; for example, salt, such as sodium
chloride or calcium chloride, is sprinkled on icy roads to lower the freezing point of water and melt the snow or ice. The
freezing point is lowered, or depressed, in proportion to the amount of salt dissolved.
Chromatography is a powerful, commonly used method to separate substances for analysis, including DNA, protein, and metal
ions. The principle takes advantage of a moving solvent and a stationary substrate to induce separation. A useful, interesting
example is paper chromatography. In this laboratory technique a mixture of solutes, such as ink dyes, is applied to a sheet of
chromatographic paper. One end of the paper is dipped in a solvent that moves (wicks) up or along the paper. Solutes (the
various ink dyes, for example) separate into bands of colors. Solutes with great affinity for the paper move little, those
with less move more, and those with very little affinity may travel with the leading edge of the solvent.
Mixtures can sometimes be separated by distillation, which capitalizes on differences in the forces holding molecules in a
liquid state. Crude oil, for example, is processed by commercial refineries (by a catalytic reaction called “cracking”) and
separated by heat distillation to give a variety of commercial products, from highly volatile kerosene and gasoline to heavier
oils used to lubricate engines or to heat homes.