1. Solutions Chapters 7 & 14 textbook

2. Hexane and Water demo

3. What did you observe and why?

4. Solutions Homogeneous mixture of substances in the same physical state
Atoms, ions, or molecules of one substance (solute) are spread uniformly throughout a second substance (solvent) For example:

5. Types of solutions: solutions are not always solids dissolved in liquids- there are many types

6. Properties of Solutions
Homogeneous mixtures
Clear and do not disperse light
Can be colored
Will not settle on standing
Will pass through a filter unchanged
Some solutions are electrolytes

7. Solubility
How much of a solute will dissolve in a certain amount of solvent at a certain temperature
Soluble: materials with a high solubility; dissolves
Insoluble: materials with low solubility

8. Factors that Affect Solubility
Nature: “Like dissolves like”

9. Factors that Affect Solubility
Temperature Solids become more soluble with increased temperature Gases become more soluble with decreased temperature Table F

10. Factors the Affect Solubility
Pressure Little to no effect on solubility of solid or liquid solutes Increased pressure increases solubility of gases Decreased pressure decreases solubility of gases

11. Table F: Predicting Solubility
Table F shows the general solubility rules for various solutes. Read the headings on the columns. Determine what they mean and how to apply the information to certain circumstances.

12. Solubility Curves: Table G
Table G indicates the solubility of certain substances at different temperatures.
Use the graph to determine if a solution is saturated, unsaturated or supersaturated
Use the graph to determine how much solute can be dissolved

13. Concentration of Solutions
Aside from using descriptive terms, like saturated, supersaturated and unsaturated, concentration can be quantified using molarity.
Molarity (M): the number of moles of solute per liter of solution
Molarity = moles of solute
liters of solution

14. Practice Question
What is the molarity of a solution that contains 4.0 molesof NaOH in .50L of solution?

15. Preparation of Solutions
I want to make one liter of a 2M solution of NaCl(aq).
Do I:
Measure out 2 moles of NaCl and put it into a flask containing one liter of water
Measure out 2 moles of NaCl, place it into a flask, and add enough water until the volume of the flask reads 1L

16. Molarity by Dilution M1V1 = M2V2
A substance with known molarity can be diluted to a different molarity using this formula

17. Molarity by Dilution Practice Problem
If you dilute 175 mL of a 1.6 M solution of LiCl to 1.0 L, determine the new concentration of the solution.

18. Molality Moles of solute/kg of solvent
Useful for large concentrations whereas

19. Molality Practice Problem
Calculate the molality of a solution 8.53 g benzene, C6H6, dissolved in 20.6 g carbon tetrachloride CCl4.

20. Concentration of Solutions
PPM – parts per million- used for solutions with extremely low concentrations
ppm= mass of solute x 1,000,000
mass of solution

21. Practice Question
What is the concentration in ppm of a 100 gram solution that contains 2.5 g of NaCl?

22. Colligative Properties
properties of solutions that depend upon the ratio of the number of solute particles to the number of solvent molecules in a solution
the presence of solute influences properties such as boiling point and freezing point
Boiling point rises
Freezing point decreases
The number of particles in solute impacts the magnitude of change

23. Colligative Properties
Which of the following will have the lowest freezing point?
1M C6H12O6
1M NaCl
1M CaCl2
(answer is C- more particles!)