1. I. The Nature of Solutions
Ch Solutions

2. A. Definitions Solute - substance being dissolved
Solution - homogeneous mixture
Solute - substance being dissolved
Solvent – the dissolving medium - present in greater amount

3. A. Definitions
Universal Solvent - H2O
Solute - KMnO4

4. A. Definitions Types of Mixtures
Solutions can exist as gases, liquids or solids.

5. A. Definitions
Examples of Types of Solutions

6. Alloys
Alloys are preferred over pure substances since they are more resistant to corrosion and it increase strength and hardness.
Steel: Fe/C
Brass: Cu/Zn
Bronze: Cu/Sn
Jeweler’s gold: Au/Cu or Au/Ag
Dental Amalgam: Hg/Ag/Zn

7. A. Definitions Suspensions(heterogeneous):
If the particles in a solvent are so large that they settle out unless the mixture is constantly stirred or agitated, the mixture is called a suspension.
Example: Jar of
Muddy Water, Orange Juice,
Italian dressing

8. A. Definitions Colloids (heterogeneous)
Particles that are intermediate in size between those in solutions and suspensions from mixtures known as colloidal dispersions. Do not Settle out.

9. A. Definitions
Tyndall Effect helps distinguish between colloids and solutions.
Occurs when light is scattered by colloidal particles dispersed in a transparent medium.

10. B. Solvation
Solvation – the process of dissolving
solute particles are surrounded by solvent particles
First...
solute particles are separated and pulled into solution
Then...

11. B. Solvation Non- Electrolyte Weak Electrolyte Strong Electrolyte+
sugar - +
acetic acid - +
NaCl
Non-
Electrolyte
Weak
Electrolyte
Strong
Electrolyte
solute exists as
molecules only
solute exists as
ions and
molecules
solute exists as
ions only
DISSOCIATION
IONIZATION

12. NaCl(s)  Na+(aq) + Cl–(aq)
B. Solvation
Dissociation
separation of an ionic solid into aqueous ions
NaCl(s)  Na+(aq) + Cl–(aq)

13. HNO3(aq) + H2O(l)  H3O+(aq) + NO3–(aq)
B. Solvation
Ionization
breaking apart of some polar molecules into aqueous ions
HNO3(aq) + H2O(l)  H3O+(aq) + NO3–(aq)

14. B. Solvation C6H12O6(s)  C6H12O6(aq) Molecular Solvation
molecules stay intact
C6H12O6(s)  C6H12O6(aq)

15. B. Solvation
“Like Dissolves Like”
NONPOLAR
POLAR

16. B. Solvation Soap/Detergent polar “head” with long nonpolar “tail”
dissolves nonpolar grease in polar water

17. no more solute dissolves SUPERSATURATED SOLUTION
C. Solubility
UNSATURATED SOLUTION
more solute dissolves
SATURATED SOLUTION
no more solute dissolves
SUPERSATURATED SOLUTION
becomes unstable, crystals form heated
concentration

18. C. Solubility Factors affecting (increasing) the rate of Dissolution
Increasing surface area (crush)
Agitation – Stirring or shaking
Increasing the temperature
Example – Sweet Tea

19. C. Solubility Solubility
maximum grams of solute that will dissolve in 100 g of solvent at a given temperature
varies with temp
based on a saturated soln

20. C. Solubility Solubility Curve
shows the dependence of solubility on temperature

21. C. Solubility Gases are more soluble at... low temperatures &
Solids are more soluble at...
high temperatures.
Gases are more soluble at...
low temperatures &
high pressures
(Henry’s Law).
EX: nitrogen narcosis, the “bends,” soda

22. II. Concentration
Ch Solutions

23. A. Concentration The amount of solute in a solution.
Describing Concentration
% by mass - medicated creams
% by volume - rubbing alcohol
ppm, ppb - water contaminants
molarity - used by chemists
molality - used by chemists

24. A. Concentration

25. B. Molality
mass of solvent only
1 kg water = 1 L water

26. B. Molality 75 g MgCl2 1 mol MgCl2 95.21 g MgCl2 1 0.25 kg water
Find the molality of a solution containing 75 g of MgCl2 in 250 mL of water.
75 g MgCl2
1 mol MgCl2
95.21 g MgCl2 1
0.25 kg water x x
= 3.2 m MgCl2

27. B. Molality 1.54 mol NaCl 1 kg water 58.44 g NaCl 1 mol NaCl
How many grams of NaCl are req’d to make a 1.54m solution using kg of water?
1.54 mol NaCl
1 kg water
58.44 g NaCl
1 mol NaCl
0.500 kg water x x
= 45.0 g NaCl

28. C. Dilution
Preparation of a desired solution by adding water to a concentrate.
Moles of solute remain the same.

29. C. Dilution GIVEN: M1 = 15.8M V1 = ? M2 = 6.0M V2 = 250 mL WORK:
What volume of 15.8M HNO3 is required to make 250 mL of a 6.0M solution?
GIVEN:
M1 = 15.8M
V1 = ?
M2 = 6.0M
V2 = 250 mL
WORK:
M1 V1 = M2 V2
(15.8M) V1 = (6.0M)(250mL)
V1 = 95 mL of 15.8M HNO3

30. I. Compounds in Aqueous Solution
Ch. 13 – Ions in Aqueous Solutions
I. Compounds in Aqueous Solution

31. A. Definitions
Dissociation – when a compound that is made of ions dissolves in water

32. B. Dissociation – Example Problem
Write the equation for the dissolution of aluminum sulfate, Al2(SO4)3 , in water. How many moles of aluminum ions and sulfate ions are produced by dissolving 1 mol of aluminum sulfate? What is the total number of moles of ions produced by dissolving 1 mol of aluminum sulfate?

33. B. Dissociation – Example Solution
Sample Problem A Solution
Given: amount of solute = 1 mol Al2(SO4)3
solvent identity = water
Unknown: a. moles of aluminum ions and sulfate ions
b. total number of moles of solute ions produced
Solution:

34. C. Solubility Precipitation Reactions:
Reactions in which one of the products are considered insoluble, thus precipitating out.
How do we decide if a compound is in soluble?

35. C. Solubility
Predicting Solubility (Solubility Rules)

36. C. Solubility KBr PbCO3 NH4OH KBr(aq) PbCO3(s) NH4OH(aq) Soluble 
Insoluble 
Soluble 
NH4OH(aq)

37. D. Net Ionic Equations
Reactions of ions in aqueous solution are usually represented by net ionic equations.
A net ionic equation includes only compounds and ions that undergo a chemical change in a rxn.
Ions that do not take part in the rxn and are found on both sides of the reaction are called spectator ions.

38. E. Writing Net Ionic Equations
Molecular Equation:
Cd(NO3)2(aq) + (NH4)2S(aq)  CdS(s) + 2NH4NO3(aq)
Complete Ionic Equation:
Cd2+(aq) + 2NO3-(aq) + 2 NH4+(aq) + S2-(aq)
 CdS(s) + 2NH4+(aq) + 2NO3-(aq)
Net Ionic Equation:
Cd2+(aq) + S2-(aq)  CdS(s)

39. II. Colligative Properties
Ch. 13 – Ions in Aqueous Solutions

40. A. Definition Colligative Property
property that depends on the concentration of solute particles, not their identity

41. B. Types Freezing Point Depression (tf)
f.p. of a solution is lower than f.p. of the pure solvent
Boiling Point Elevation (tb)
b.p. of a solution is higher than b.p. of the pure solvent

42. Freezing Point Depression
B. Types
Freezing Point Depression

43. Boiling Point Elevation
B. Types
Boiling Point Elevation
Solute particles weaken IMF in the solvent.

44. B. Types Applications salting icy roads making ice cream antifreeze
cars (-64°C to 136°C)
fish & insects