1. West Valley High School
SOLUTIONS
Chapter 12
West Valley High School
General Chemistry
Mr. Mata

2. Standard 5
Students know that temperature, pressure, and surface area affect the dissolving process.

3. Essential Question:
What are the components of a solution and how do solutions, suspensions, and colloids differ from one another?

4. What is a Solution?
Solution = homogeneous mixture of two or more substances.
(solute & solvent)
Solute = substance being dissolved.
Solvent = substance doing the dissolving.
Homogeneous mixture = completely dissolved & uniform solute in solvent
Aqueous solution = solution in which the solvent is water.

5. Parts of a Solution

6. Homogeneous vs. Heterogeneous
24-karat gold is pure gold = homogeneous
14-karat gold is an alloy (mixture) Au, Ag, Cu = heterogeneous
14-karat gold is 14/24 (58.3%) gold

7. Solubility Terminology
Soluble = substance that can be dissolved.
Insoluble = substance that cannot be dissolved.
Solubility = measure of how much solute will dissolve in solvent.
Miscible = two liquids that dissolve in each other (ex: water & ethanol).
Immiscible = two liquids that don’t dissolve in each other (ex: H2O & oil).

8. Immiscible Liquids

9. Solubility Terminology
SATURATED—contains the maximum amount of solute.
UNSATURATED—contains less solute than a saturated solution.
SUPERSATURATED—contains more solute than it should.

10. Solution Saturations

11. Factors affecting Solubility
Stirring (agitation) increases solubility.
Surface Area (particle size) smaller size increases surface area: increases sol.
Pressure (gases) increased pressure increases gas solubility.
Temperature (solids & gases).
solids: temp increase = increases solubility
gases: temp increase = decrease solubility

12. Solution Concentration
Concentration: measure of the amount of solute that is dissolved in a given quantity of solvent.
Dilute solution = solution that contains small amount of solute.
Concentrated solution = solution that contains a large amount of solute.
Molarity (M) = moles of solute/L of soln
Units = M or moles/Liter (mol/L).

13. Suspensions
Suspension – particles in a solvent are so large that they settle to bottom unless agitated.
Ex: muddy water
Soil particles will sink to bottom.
Can be separated from heterogeneous mixtures by filtering.

14. Colloids
Particles are intermediate in size between those in solutions and suspensions.
1 nanometer (nm) to 1000 nm.
Cause mixture to look “cloudy”.
Ex: mayonnaise
Egg yolk keeps the oil droplets dispersed.

15. MOLARITY Molarity (M) = moles of solute Liters of solution
Units in mol/L or M

16. A saline solution contains 0. 90 g NaCl in exactly 100 mL of solution
A saline solution contains 0.90 g NaCl in exactly 100 mL of solution. What is the molarity of the solution?
M = moles solute
Liters of solution
0.90 g NaCl x 1 mol NaCl = 0.02 mol NaCl
58 g NaCl
100 mL x 1 L = 0.1 L
1000 mL
M = 0.02 mol = 0.2 mol/L or 0.2 M
0.1 L

17. A solution contains 325 g CaCl2 in exactly 2500 mL of solution
A solution contains 325 g CaCl2 in exactly 2500 mL of solution. What is the molarity of the solution?
M = moles solute
Liters of solution
325 g CaCl2 x 1 mol CaCl2 = mol CaCl2
110 g CaCl2
2500 mL x 1 L = 2.5 L
1000 mL
M = 2.95 mol = 1.2 mol/L or 1.2 M
2.5 L

18. How many moles of solute are present in 1.5 L of 0.24 M Na2SO4?
M = mol -> mol = ML L
0.24 M Na2SO4 = 0.24 mol/L Na2SO4
Mol = (0.24 mol/L) (1.5L) = 0.36 mol

19. How many moles of solute are present in 20 L of 12 M H2SO4?
M = mol -> mol = ML L
12 M H2SO4 = 12 mol/L H2SO4
Mol = (12 mol/L) (20L) = 240 mol

20. Percent Solutions
What is the percent by volume of ethanol in the final solution when 85 mL of ethanol is diluted with 250 mL of water?
%v/v = volume of solute x 100
solution volume
%v/v = 85 mL ethanol x 100 =
250 mL H2O
= 34% ethanol (v/v)

21. Percent Solutions
What is the percent by volume of ethanol in the final solution when 300 mL of ethanol is diluted with 600 mL of water?
%v/v = volume of solute x 100
solution volume
%v/v = 300 mL ethanol x 100 =
600 mL H2O
= 50% ethanol (v/v)

22. Parts per Million Parts per million (ppm)
Aqueous solutions: 1 ppm = 1000 ng/L
The federal limit of lead in tap water is ppm. Express this concentration in ng/L.
0.015 ppm x 1000 ng/L = 15 ng/L
1 ppm

23. Parts per Million
The federal limit of mercury in tap water is ppm. Express this concentration in ng/L.
ppm x 1000 ng/L = .2 ng/L
1 ppm

24. Chapter 12 SUTW Prompt
Describe the differences between an unsaturated, saturated, and supersaturated solution.
Complete a sentence paragraph using the SUTW paragraph format. Hilight using green, yellow, and pink.
Due Date: Tomorrow (start of class).