Solutions!
Classification of Matter
MATTER
Mixtures
= a physical blend of 2 or more components
- 2 types:
(1) Homogenous Mixture = ____________________________
- Homogenous Aqueous Mixture:
________________
(2) Heterogenous Mixture = ____________________________
- Heterogenous Aqueous Mixtures:
Suspensions
Colloids
Separating Physical Mixtures
1.) Filtration
=______________________________________________________
______________________________________________________
2.) Distillation
=____________________________________________________
_____________________________________________________
3.) Chromatography
= __________________________________
__________________________________
Solutions
= a homogenous mixture of substances in the same physical
state
**We will be discussing aqueous solutions mostly.**
___________________
Solvent =_______________________
Solute = _______________________
 can be atoms, ions, or molecules
How do solutions form?
http://www.chem.iastate.edu/group/Gr
eenbowe/sections/projectfolder/flashfil
es/thermochem/solutionSalt.html
When an ionic compound dissolves in water:
**solvation = _________________________________________
http://www.mhhe.com/ph
yssci/chemistry/essential
chemistry/flash/molvie1.s
wf
- Polar compounds can also readily dissolve in water.
- Nonpolar compounds cannot dissolve in water.
 Why not?
**But….nonpolar compounds can dissolve in ___________
solvents.
“_____ dissolves ____!”
________ compounds
will dissolve in a polar
solvent, but not a
nonpolar solvent.
________ compounds
will dissolve in a polar
solvent, but not a
nonpolar solvent.
__________ compounds
will dissolved in a
nonpolar solvent, but not
a polar solvent.
- Electrolyte
= ________________________________________
_________________________________________
**All ionic compounds are electrolytes because:
________________________________________
- Nonelectrolyte
= _________________________________________
_________________________________________
**Most compounds are nonelectrolytes because:
_________________________________________
Factors Affecting How Fast
Particles Dissolve
1.) Stirring makes compounds dissolve faster.
2.) Higher temperatures make compounds dissolve faster.
3.) Smaller-sized particles dissolve faster.
Solubility
- Solubility
= ___________________________________________
___________________________________________
___________________________________________
- usually expressed in grams of solute per 100g of solvent
- Factors Affecting Solubility
1.) Nature of solute & solvent:
**Remember: “Like dissolves like.”**
2.) Temperature:
- As temperature
in water.
- As temperature
in water.
, most solids become ____ soluble
, most gases become ____ soluble
3.) Pressure:
- Pressure has little to no effect on solubility of liquids
& solids.
- As pressure , solubility of gases in liquids ______
Solubility Curve
-
Shows the relationship of grams of
solute that may be dissolved at
various temperatures.
-
Each line represents the maximum
amount of that substance that can be
dissolved at a given temperature.
-
Lines show an increase in the
solubility of solids as temperature
increases, and a decrease in the
solubility of gases as temperature
increases.
Sample Individual Solubility
Curve- Potassium nitrite
Saturated Solution:
= contains the maximum amount of solute
for a given quantity of solvent at a constant
temperature & pressure
 if additional solute is added, it will not
dissolve; rather it will precipitate out
Unsaturated Solution:
= a solution that contains less solute than a
saturated solution at a given temperature &
pressure
 if additional solute is added, it will
dissolve
Supersaturated Solution:
= contains more solute than it can
theoretically hold at a given temperature
 crystallization will be initiate if a very
small “seed crystal” of solute is added
**very unstable**
http://www.metacafe.com/watch/4
04010/rapid_crystallization_supers
aturated_solution_demo/
Colligative Properties
of Solutions
Colligative Property = ________________________
________________________
________________________
 Vapor Pressure Lowering
 Boiling Point Elevation
 Freezing Point Depression
Vapor Pressure Lowering
Remember:
Vapor pressure = __________________________________
**A solution always has a lower vapor pressure than the pure solvent.**
Why??
Boiling Point Elevation
Remember: A low vapor pressure means more energy is needed to get
the substance to boiling (vapor pressure = atmospheric pressure).
So…..
**A solution always has a higher boiling point than the pure solvent.**
Freezing Point Depression
**A solution always has a lower freezing point than the pure solvent.**
Why???
Vs.
The magnitude of a colligative property change is proportional to the #
of solute particles dissolved in the solvent.
So, the greater the # of particles:
 the lower the vapor pressure goes
 the higher the boiling point goes
 the lower the freezing point goes
Ionic solids, therefore, produce a greater change in colligative properties:
C6H12O6 (s)  C6H12O6 (aq)
NaCl (s)  Na+(aq) + Cl-(aq)
CaCl2(s)  Ca +(aq) + 2Cl-(aq)