1. CHAPTER 15 – SOLUTIONS
SOLUTION – A homogeneous mixture
SOLVENT – The major component
SOLUTE – The minor component
Why will 2 substances form a solution?
7B-1 (of 26)

2. LIKES DISSOLVE LIKES
Polar substances dissolve other polar substances
Nonpolar substances dissolve other nonpolar substances
Polar and nonpolar substances do not mix
Lava Lamps
7B-2

3. Dissolves polar substances that can δ- δ- δ+ δ- δ- δ- δ+ δ+ δ-
Water
Carbon tetrachloride
Polar
Nonpolar
Dissolves polar substances that can
H-Bond to water, and ionic substances
Dissolves nonpolar substances
NH3, C6H12O6, C2H5OH, HF, NaCl
Grease, Oil, CxHy
7B-3

4. Soluble polar compounds (such as alcohols or sugars) are NONELECTROLYTES because they do not produce ions in solution
Exception: Acids (which are polar compounds that do produce ions in solution) can be STRONG or WEAK ELECTROLYTES
Soluble ionic compounds are STRONG ELECTROLYTES because they produce many ions in solution
7B-4

5. Water dissolves ionic substances because negative ends of H2O’s attract cations, and positive ends of H2O’s attract anions
HYDRATION – Attachment of H2O molecules to dissolved ions
7B-5

6. SOLUBILITY
SOLUBILITY – The maximum mass of a solute that dissolves in 100 g of solvent at a particular temperature
SOLUBLE – A substance in which at least 1 g dissolves per 100 g of solvent
INSOLUBLE – A substance in which less than 0.1 g dissolves per 100 g of solvent
7B-6

7. SATURATED – A solution that contains as much dissolved solute as possible
Dissolving Rate
Crystallizing Rate
SOLUTION EQUILIBRIUM – When the rates of dissolving and crystallizing are equal
A saturated solution is in solution equilibrium
7B-7

8. PROPERTIES OF SOLUTIONS
(1) Equilibrium Vapor Pressure
A liquid’s equilibrium vapor pressure is lowered by having a solute dissolved in it
Temp (ºC) EVP of pure water
(torr)
EVP of a dilute salt
water solution (torr) 10 20 30
9.2
17.5
31.8
9.1
17.4
31.6
100
760.0
757.2
7B-8

9. (2) Boiling Points
A liquid’s boiling point is raised by having a solute dissolved in it
Solution Boiling Point (ºC)
Pure H2O
Dilute Salt Water
Conc. Salt Water
100.0
100.1
101.0
7B-9

10. (3) Freezing Points
A liquid’s freezing point is lowered by having a solute dissolved in it
Solution Freezing Point (ºC)
Pure H2O
Dilute Salt Water
Conc. Salt Water
0.0
- 0.4
- 3.7
Arctic Ocean
Freezing Point: 28ºF
7B-10

11. CONCENTATION UNITS
MASS PERCENT – The mass of solute per mass of solution, times 100
Mass Percent =
Mass Solute x 100
__________________
Mass Solution
5.00 g of salt is dissolved in g of water. Calculate the mass percent.
5.00 g NaCl x 100
_____________________
105.0 g Solution
= %
7B-11

12. Calculate the mass of sugar in 50
Calculate the mass of sugar in 50.0 g of a sugar-water solution that is 15% sugar by mass.
x g sugar x 100
___________________
50.0 g solution
= 15 %
x g sugar =
15 x g solution
__________________________
100
x g sugar =
7.5 g
7B-12

13. MOLARITY (M) – The MOLES of solute per liter of solution
Moles Solute
__________________
Liter Solution
M = n
___ V
Calculate the molarity of a solution that has 4.50 g of potassium nitrate dissolved in enough water to make 100. mL of solution.
4.50 g KNO3
x mol KNO3
__________________
g KNO3
= mol KNO3
mol KNO3
_______________________
0.100 L solution
= M KNO3
7B-13

14. STANDARD SOLUTION – A solution of known concentration
Calculate the molarity of a solution that has 10.0 g of lithium sulfate dissolved in enough water to make 250. mL of solution.
10.0 g Li2SO4
x mol Li2SO4
____________________
g Li2SO4
= mol Li2SO4
mol Li2SO4
________________________
0.250 L solution
= M Li2SO4
7B-14

15. Calculate the mass of magnesium fluoride needed to produce 500
Calculate the mass of magnesium fluoride needed to produce 500. mL of a 3.00 M solution.
M = n
___ V
MV = n
3.00 mol MgF2
___________________
L solution
x L solution
= mol MgF2
1.500 mol MgF2
x g MgF2
_________________
mol MgF2
= g MgF2
7B-15

16. Calculate the mass of sodium bromide dihydrate needed to produce 750
Calculate the mass of sodium bromide dihydrate needed to produce 750. mL of a M solution.
M = n
___ V
MV = n
0.200 mol NaBr 2H2O
_____________________________
L solution
x L solution
= mol NaBr  2H2O
mol NaBr  2H2O
x g NaBr  2H2O
___________________________
mol NaBr  2H2O
= g NaBr  2H2O
7B-16

17. Calculate the concentrations of each ion in a 0
Calculate the concentrations of each ion in a M aluminum fluoride solution.
AlF →
(aq)
Al F-
(aq)
(aq)
AlF3 completely dissociates, 
0.250 M AlF3 x 1 = M Al3+
0.250 M AlF3 x 3 = M F-
7B-17

18. Calculate the concentrations of each ion in a 0
Calculate the concentrations of each ion in a M iron (III) sulfate solution.
Fe2(SO4) →
(aq)
2Fe SO42-
(aq)
(aq)
Fe2(SO4)3 completely dissociates, 
0.100 M Fe2(SO4)3 x 2 = M Fe3+
0.250 M Fe2(SO4)3 x 3 = M SO42-
7B-18

19. REACTIONS IN SOLUTION
Calculate the mass of silver that can be produced when magnesium metal reacts with 50.0 mL of a M silver nitrate solution.
Mg AgNO → 2
Mg(NO3) Ag 2
50.0 mL
0.400 M
x g
2 mol
2 mol
0.400 mol AgNO3 x L sol’n
_____________________
L sol’n
x mol Ag
________________
2 mol AgNO3
x g Ag
_____________
mol Ag
= g Ag
7B-19

20. NEUTRALIZATION REACTION – A reaction between an acid and a base
Calculate the mass of sodium hydroxide needed to neutralize 100. mL of M nitric acid.
NaOH HNO →
NaNO H(OH)
x g
100. mL
0.175 M
1 mol
1 mol
0.175 mol HNO3 x L sol’n
___________________
L sol’n
x 1 mol NaOH
_______________
1 mol HNO3
x g NaOH
_________________
mol NaOH
= g NaOH
7B-20

21. Calculate the molarity of copper (I) ions in a 75
Calculate the molarity of copper (I) ions in a 75.0 mL sample if the sample reacts with a solution of sulfide ions to produce 1.25 g of copper (I) sulfide.
Cu S → 2
Cu2S
75.0 mL
x M
1.25 g
2 mol
2 mol
1.25 g Cu2S
x 1 mol Cu2S
_________________
g Cu2S
x 2 mol Cu+
______________
1 mol Cu2S x
_________________
L sol’n
= M Cu2+
M = n / V
7B-21

22. Calculate the molarity of lead (II) ions in a 25
Calculate the molarity of lead (II) ions in a 25.0 mL sample if it reacts completely with 20.0 mL of a M iodide solution.
Pb I → 2
PbI2
25.0 mL
x M
20.0 mL
0.300 M
1 mol
2 mol
0.300 mol I- x L sol’n
_______________
L sol’n
x 1 mol Pb2+
_____________
2 mol I- x
___________________
L sol’n
= M Pb2+
M = n / V
7B-22

23. Calculate the volume of 0. 200 M sulfuric acid needed to neutralize 25
Calculate the volume of M sulfuric acid needed to neutralize 25.0 mL of a M potassium hydroxide solution.
H2SO KOH → 2 2
H(OH) K2SO4
x mL
0.200 M
25.0 mL
0.150 M
1 mol
2 mol
0.150 mol KOH x L sol’n
___________________
L sol’n
x 1 mol H2SO4
________________
2 mol KOH
x L sol’n
_____________________
0.200 mol H2SO4
V = n / M
= L H2SO4 solution
= mL H2SO4 solution
7B-23

24. THE REVIEW
Solubility Rules and Strong Acids
Dissociation and Ionization
Electrolytes: Strong and Weak
Precipitate
Molecular, Ionic, and Net ionic Equations (with phases) for
Precipitation Reactions
Acid-Base Reactions
7B-24

25. THE REVIEW
Solution, Solvent, Solute
Likes Dissolve Likes
Hydration
Solubility
Solution Equilibrium, Saturated Solution
Soluble, Insoluble, Miscible, Immiscible
Mass Percent
Molarity
Molarity of Ions
Calculations Involving reactions in Solution
7B-25