1. SOLUTIONS
Chapter 13 and 14

2. VOCABULARY Solution Solute Solvent Soluble Solubility
Solution equilibrium
Saturated solution
Supersaturated solution
Solvation (hydration)
Electrolyte

3. The Solution Process Factors affecting rate of dissolution
1. Increasing solute surface area
Increase by crushing the solute
Exposes more solute to solvent and dissolution occurs more rapidly
2. Agitation
Helps disperse the solute particles and bring fresh solvent to the surface of the solute
3. Heating a solvent
Increases the kinetic energy of the solvent particles causing more collisions with the solute

4. SOLUBILITY
Defined as: the amount of a substance required to form a saturated solution with a specific amount of solvent at a specified temperature.
Usually reported as g/ 100 g solvent
Ex. Sugar 204 grams per 100 g of water at 20ºC.

5. What affects solubility? POLARITY
General rule: “likes dissolve likes”
Non-polar solvents dissolve non-polar solutes
Miscible
Benzene
CCl4
C6H5CH3 (tolulene)
Polar solvents dissolve polar and ionic solutes
H2O and NaCl
C2H5OH – ethanol (slightly polar)
will NOT dissolve ionic compounds

6. TEMPERATURE affects solubility of solids

7. Gas solubility
Henry’s law – gas solubility increases as the partial PRESSURE of the gas above the solvent increases.
Gases become less soluble as temperature increases.

8. CONCENTRATION of SOLUTIONS
A measure of the amount of solute in a given amount of solvent or solution. Can be expressed using:
Molarity
molality
Mass %
Parts per million (ppm)
Parts per billion (ppb)

9. MOLARITY Number of moles of solute/ Liters of solution. Symbolized: M
M = moles solute/ L soln.
Ex. 6.0 M HCl

10. MOLARITY
1. What is the molarity of a solution prepared by dissolving grams of sodium carbonate in enough water to make 1.0 L of solution.
2. Given 35.0 ml of a 0.50 M solution of HCl, how many moles of HCl are present?

11. examples 3. How many grams of NaCl are present in a 3.0 M solution?
4. What volume of 3.00 M H2SO4 is needed for a reaction that requires grams of sulfuric acid?

12. molality
The concentrations of a solution expressed in moles of solute per kilogram of solvent.
Used for freezing point and boiling point problems.

13. examples
Ex. What is the molality of a solution prepared by mixing 15 grams of glucose into 500 grams of water?
What is the molality of a salt solution made by adding 5.0 kg of calcium chloride to 200 kg of ice?

14. Colligative properties
What are the effects of adding a solute to a solvent?
Colligative properties – depend on the number of particles in solution, not the type of particles.
How many particles are present when the following dissolve?
NaCl
C6H12O6
CaCl2

15. Boiling point elevation
The temperature at which the vapor pressure of the liquid = the atmospheric pressure
The boiling point of a solvent will increase when a non-volatile solute is added.
Why?
Particles block the surface of the solution, making it harder for the solvent (g) to escape. More ke is required, so the temperature must increase.
How much?
∆Tb = i Kb m
Where i = number of particles
Kb = boiling point elevation constant
(+.51°C/molal for water)
m = molality

16. examples
What is the boiling point elevation when grams of sucrose is added to grams of water?
What is the boiling point elevation when grams of sodium chloride is added to 2.0 kg of water?

17. Freezing point depression
Freezing point – the temperature at which a solution forms a solid from the (aq) phase
The freezing point of a solvent will decrease when a non-volatile solute is added.
Why?
Solute particles interfere with the organization of the solid. In order to form the solid around the solute particles, the kinetic energy must decrease, so the freezing point is lowered.
How much?
∆Tf = i Kf m
Where i = number of particles
Kf = freezing point depression constant
(-1.86°C/molal for water)
m = molality

18. examples
What is the freezing point depression when 500. grams of sodium chloride is added to g of water? What is the freezing point depression when 50.0 grams of calcium chloride is added to 500. grams of water?

19. STOICHIOMETRY
How many ml of 3.0 M NaOH are needed to neutralize 5.0 grams of acetic acid found in a vinegar solution? What is the M of the vinegar?
How many grams of Mg can be dissolved by ml of 6.0 M HCl? How much gas will be produced by this reaction at STP?

20. STOICHIOMETRY
5.0 ml of 6.0 M HCl reacts with 25.0 ml .10 M NaOH. How much water will be produced?
How many ml 0.10 M NaOH should be used to neutralize the 5.0 ml of HCl?