1. Chapter 18: Solution Chemistry
(Also including some Ch. 17!)

2. A few things you need to recall…
Ionic = metallic element + nonmetallic element
Covalent = nonmetal + nonmetal
Polar
Nonpolar
Examples:

3. Solutions:
Aqueous Solutions: Water that contains a dissolved substance.
Kool Aid
Salt water
Magnesium chloride solution
Vinegar

4. Solutions are made up of Solvents and Solutes:
Solute: The dissolving substance
Solvent: The medium in which a solute is dissolved.
Water is the most
common solvent

5. Dissolving NaCl

6. Dissolving Ionic Compounds

7. A molecular look at dissolving an ionic compound in water
Solvation: process that occurs when a compound is dissolved in water.

8. Solute or Solvent?

9. Oil/Water Activity
In your beaker add about 20 mL of oil to 20 mL of water.
Do the two substances mix?
Add 4-5 drops of food coloring to the beaker? What happens?
Based on your experiment, does food coloring have properties that are similar to water or similar to oil?

10. Water is a polar compound
Likes Dissolve Likes
Polar molecules dissolve in Polar solvents.
Nonpolar solutes dissolve in nonpolar solvents.
Ionic compounds and polar covalent compounds dissolve the best in water. Why?
Water is a polar compound

11. Oil and vinegar are immiscible – they do not dissolve in each other.
Mixing Oil and Water
Polar
Vinegar (acetic acid)
Non-Polar
Oil and vinegar are immiscible – they do not dissolve in each other.
Olive Oil

12. Making Solutions

13. Factors that affect dissolving rate
How do you make sugar dissolve faster in iced tea?
1) Stirring = Agitation
Changes rate, but not how much dissolves.

14. Factors that affect dissolving rate
Does sugar dissolve faster in hot tea or cold tea?
2)Temperature
Kinetic Energy of water molecules increases; more collisions with surface of sugar crystals

15. Factors that affect dissolving rate
Does granular sugar or a sugar cube dissolve fastest?
3) Particle Size
More solute is exposed to water, dissolves faster

16. Homogeneous vs. Heterogeneous
Homogeneous = evenly mixed; same throughout
Heterogeneous = unevenly mixed; not
the same throughout

17. Solubility: How much dissolves?
Solubility: The amount of solute that will dissolve in a solvent at a given temperature.
Very temperature dependent.
Usually expressed in
g/100mL (or g/100g H2O)

18. Examples:
Example #1: What is the solubility of sodium chloride at 70 °C?

19. Example 2:
Example #2: At 25 °C, how many grams of potassium nitrate will dissolve in 200 mL water?

20. Practical Applications
What are the optimum conditions to explode a can of coke on your little brother?
Why do divers have to worry about
how fast they return to the ocean
surface?

21. Warm Up 12/02/08 1. How many moles are in 510 g of AgNO3?
2. List the 3 factors that affect how fast a substance dissolves.

22. Types of Solutions:
Saturated Solution: Contains the max amount of solute at a given temperature.
No more can be dissolved
Unsaturated: Contains less than max amount of solute

23. Types of Solutions
Supersaturated: Solutions that hold more solute than possible.

24. Real life supersaturation experience…
Rock Candy!

25. Factors Affecting Solubility
Temperature
Solids: More soluble in hot solvent
Gases: More soluble in cold solvent
Pressure
Gases: More soluble at high pressure

26. Concentration of Solutions
Concentration is the amount of solute per amount of solvent.
To make Kool Aid:
2 Scoops Kool Aid
1 Quart Water

27. Describing Solutions Version 1: No Math! (Qualitative) Dilute :
Low concentration of solute
Concentrated :
High concentration of solute
½ scoop Kool Aid
2 Quarts Water
2 ½ scoop Kool Aid
2 Quarts Water

28. Common Chemistry Concentrations
Version 2 (MATH )
Molarity (M)
Molality (m)
Percent Composition
%m/%v
%v/%v

29. Molarity

30. Example 1:
A solution has a volume of 2.0 L and contains 36.0 g of glucose (mm 180 g/mol). What is the molarity of the solution?

31. Example 2:
How many moles of ammonium nitrate are in 335 mL of M NH4NO3?

32. Dilutions
Used when you want a less concentrated solution.
Kool Aid Example:
Same number of moles of solute when you make a dilution:
M1 x V1 = M2 x V2
Final Volume
Of Dilute Sln
Initial Molarity
Of Concentrated
Solution
Final Molarity
Of Dilute Sln
Initial Volume

33. Example 3
Explain how to prepare 25 L of a 0.10 M BaCl2 solution, starting with solid BaCl2.
Specify the volume of the solution above to get mol of BaCl2.

34. Example 3
How many mL of a stock solution (concentrated) of 4.00 molar potassium iodide would you need to prepare 250 mL of M KI?

35. Percent Compostion %(m/v) = (mass solute (g)) ÷ (mL solution)  100%
%(v/v) = (volume solute) ÷ (L solution)  100%

36. Example 4:
Determine the %(m/v) of a solution that is 20.0 g sugar in 401 mL solution.

37. Parts per million (ppm)
ppm = (mass solute (g)) ÷ (mL solution)  1,000,000