1. Physical Properties of Solutions
Chapter 13
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2. A ____________ is a homogenous mixture of two or more substances
The ____________ is(are) the substance(s) present in the smaller amount(s)
The ____________ is the substance present in the larger amount
Types of Solutions
p.406
13.1

3. A ______________ ______________ contains the maximum amount of a solute that will dissolve in a given solvent at a specific temperature.
An ______________ ______________ contains less solute than the solvent has the capacity to dissolve.
A ______________ ______________ contains more solute than is present in a saturated solution.
Sodium acetate crystals rapidly form when a seed crystal is added to a supersaturated solution of sodium acetate.
13.1

4. Three types of interactions in the solution process:
solvent-solvent interaction
solute-solute interaction
solvent-solute interaction
DHsoln = DH1 + DH2 + DH3
13.2

5. “Like dissolves like”
Two substances with similar intermolecular forces are likely to be soluble in each other.
non-polar molecules are soluble in non-polar solvents
CCl4 in C6H6
polar molecules are soluble in polar solvents
C2H5OH in H2O
ionic compounds are more soluble in polar solvents
NaCl in H2O or NH3 (l)
oil (non-polar) and water (polar) don’t mix
13.2

6. Concentration Units
The _________________ of a solution is the amount of solute present in a given quantity of solvent or solution.
________________________
x 100%
mass of solute
mass of solute + mass of solvent
% by mass = =
x 100%
mass of solute
mass of solution
________________________
XA =
moles of A
sum of moles of all components
13.3

7. Concentration Units Continued
____________
M =
moles of solute
liters of solution
____________
m =
moles of solute
mass of solvent (kg)
13.3

8. 5.86 moles ethanol = 270 g ethanol
What is the molality of a 5.86 M ethanol (C2H5OH) solution whose density is g/mL?
m =
moles of solute
mass of solvent (kg)
M =
moles of solute
liters of solution
Assume 1 L of solution:
5.86 moles ethanol = 270 g ethanol
927 g of solution (1000 mL x g/mL)
mass of solvent = mass of solution – mass of solute
= 927 g – 270 g = 657 g = kg
m =
moles of solute
mass of solvent (kg) =
5.86 moles C2H5OH
0.657 kg solvent
= ________
13.3

9. Temperature and Solubility
Solid solubility and temperature
solubility _________ with increasing temperature
13.4

10. Temperature and Solubility
Solid solubility and temperature
solubility _________ with increasing temperature
13.4

11. ____________ ____________ is the separation of a mixture of substances into pure components on the basis of differing solubilities.
Suppose you have 90 g KNO3 contaminated with 10 g NaCl.
Fractional crystallization:
Dissolve sample in 100 mL of water at 600C
Cool solution to 00C
All NaCl will stay in solution (s = 34.2g/100g)
78 g of PURE KNO3 will precipitate (s = 12 g/100g). 90 g – 12 g = 78 g
13.4

12. Temperature and Solubility
Gas solubility and temperature
solubility usually ____________ with increasing temperature
13.4

13. ____________ and ____________ of Gases
The solubility of a gas in a liquid is proportional to the pressure of the gas over the solution (________ law).
c is the concentration (M) of the dissolved gas
c = kP
P is the pressure of the gas over the solution
k is a constant (mol L-1 atm-1) that depends only
on temperature
low P
high P
low c
high c
13.5

14. Colligative Properties of Nonelectrolyte Solutions
____________ ____________ are properties that depend only on the number of solute particles in solution and not on the nature of the solute particles.
Vapor-Pressure ____________
P1 = X1 P 1
P 1
= vapor pressure of pure solvent
X1 = mole fraction of the solvent
____________ law
If the solution contains only one solute:
X1 = 1 – X2
P 1
- P1 = DP = X2
X2 = mole fraction of the solute
13.6

15. An ______________ is one that obeys Raoult’s Law
PA = XA P A
PB = XB P B
Ideal Solution
PT = PA + PB
PT = XA P A
+ XB P B
An ______________ is one that obeys Raoult’s Law
13.6

16. < & > & PT is ______________ predicted by Raoults’s law
Force
A-B
A-A
B-B
<
&
Force
A-B
A-A
B-B
>
&
13.6

17. Fractional Distillation Apparatus
13.6

18. Boiling-Point Elevation
DTb = Tb – T b
T b is the boiling point of
the pure solvent
T b is the boiling point of
the solution
Tb > T b
DTb > 0
DTb = Kb m
m is the molality of the solution
Kb is the molal boiling-point
elevation constant (0C/m)
13.6

19. Freezing-Point Depression
DTf = T f – Tf
T f is the freezing point of
the pure solvent
T f is the freezing point of
the solution
T f > Tf
DTf > 0
DTf = Kf m
m is the molality of the solution
Kf is the molal freezing-point
depression constant (0C/m)
13.6

20. Molal Boiling-Point Elevation and Freezing-Point Depression Constants of Several Common Liquids
13.6

21. DTf = Kf m Kf water = 1.86 0C/m DTf = Kf m
What is the freezing point of a solution containing 478 g of ethylene glycol (antifreeze) in 3202 g of water? The molar mass of ethylene glycol is g.
DTf = Kf m
Kf water = C/m =
3.202 kg solvent
478 g x
1 mol
62.01 g
m =
moles of solute
mass of solvent (kg)
= ______ m
DTf = Kf m
= C/m x 2.41 m = ______0C
DTf = T f – Tf
Tf = T f – DTf
= 0 0C – C = _______0C
13.6

22. ( )
__________________ is the selective passage of solvent molecules through a porous membrane from a dilute solution to a more concentrated one.
A __________________ __________________ allows the passage of solvent molecules but blocks the passage of solvent molecules.
__________________________ (p) is the pressure required to stop osmosis.
more
concentrated
dilute
13.6

23. Osmotic Pressure (p) p = ____________ High P Low P
M is the molarity of the solution
R is the gas constant
T is the temperature (in K)
13.6

24. A cell in a/an: ___________ ___________ ___________
solution
___________
solution
___________
solution
13.6

25. Colligative Properties of _____________ Solutions
_____________ _____________ are properties that depend only on the number of solute particles in solution and not on the nature of the solute particles.
P1 = X1 P 1
Vapor-Pressure ___________
Boiling-Point _____________
DTb = Kb m
Freezing-Point ____________
DTf = Kf m
Osmotic Pressure (p)
p = MRT
13.6

26. Colligative Properties of _____________ Solutions
0.1 m NaCl solution
0.1 m Na+ ions & 0.1 m Cl- ions
_______________ _______________ are properties that depend only on the number of solute particles in solution and not on the nature of the solute particles.
0.1 m NaCl solution
0.2 m ions in solution
van’t Hoff factor (i) =
actual number of particles in soln after dissociation
number of formula units initially dissolved in soln
i should be
nonelectrolytes 1
NaCl 2
CaCl2 3
13.6

27. Colligative Properties of __________ Solutions
Boiling-Point Elevation
DTb = i Kb m
Freezing-Point Depression
DTf = i Kf m
Osmotic Pressure (p)
p = iMRT
The van’t Hoff Factor of M Electrolyte Solutions at 25ºC
13.7

28. Colloid versus solution
A ___________ is a dispersion of particles of one substance throughout a dispersing medium of another substance.
Colloid versus solution
collodial particles are much _______ than solute molecules
collodial suspension is not as ____________ as a solution
Types of Colloids
13.8

29. The Cleansing Action of Soap
13.8