Solution Chemistry
Homogeneous Mixtures
- component substances uniformly distributed throughout solutions (eg. Salt
water)
Heterogeneous Mixtures
- component substances are observably segregated
(eg. Orange Juice)
Parts of a solution:
Solvent
- substance in greater quantity
Solute
- component of less abundance
3 Types of Solutes
2 Types of Solvents
Ionic
– eg. NaCl
Polar covalent solvents
- eg. H2O
Polar Covalent
- molecules with a +’ve and a –‘ve end
- eg. Sucrose (sugar)
Non-Polar covalent
- no charges
- eg. Br2
Non-Polar covalent solvents
- no charges
- eg. paint thinner (acetone)
Like Dissolve Like
Polar or ionic/Polar………………… will mix
Non-Polar/Non-Polar……............... will mix
Polar/Non-Polar……………………..won’t mix
(Demo 16A)
Solubility & Miscibility
Unsaturated
- when a solution is able to dissolve more of a solute
Saturated
- when a solute will no longer dissolve
- at a specific temperature, only a fixed volume of solvent is capable of dissolving
a given quantity of solute.
Solubility
- amount of a substance needed to make a saturated solution at a specific
temperature.
water
0°C 10°C 20°C 30°C 40°C 50°C 60°C 70°C 80°C 90° 100°C
Al(NO3)3
60 66.7 73.9 81.8 88.7
106
132 153 160
(grams/100mL)
Supersaturated
- unstable solution with conc. higher than its normal solubility due to special
conditions i.e heat
Miscible
- when there is no apparent limit to the solubility of one material in another (eg.
H2O / CH3CH2OH)
Immiscible
- refers to substances that will not dissolve each other
Conductivity
Electrolyte
- solute that dissolves in a aqueous solution resulting in a solution that contains
ions, conducts electricity
Non-electrolyte
- solute remains undissociated, so does NOT conduct electricity
Electrical conduction in a solution requires the transferring of electrically charged
ions thru a solution
Electrolytes are typically highly soluble, ionic compounds, also includes acids
and bases
In order to conduct electricity, compounds must be liquid (unless substance is a
metal).
The higher the concentration of ions in a solution, the higher the conductivity.
General rules for Conductivity:
1. substance made of metal + non-metal  conduct
2. non-metal + non-metal  does NOT conduct
3. acid / base  conduct
4. if organic (C & H) it will not conduct UNLESS ends in “COOH”
5. sample is in liquid or aqueous form  conduct
Molecular Polarity
- refers to an uneven charge distribution caused by an unequal sharing of
electrons. Atoms must have different electronegativities.
dipole-dipole force
the attraction between oppositely charged ends of polar molecules
Two atoms with different electronegativities give rise to a dipole. E.g. H 2O
In order to be a polar molecule, the molecule must have dipole-dipole forces and
be ASYMMETRICAL (one end of the molecule differs from the other end).
Polar = asymmetrical
non-polar = symmetrical
Examples
Polar
HCl
CH3Cl
H2O
BH3
C2Cl6
I2BBr
Non-polar
BeF2
CH4
Solvation of Ionic Solids
Solvation
- interaction between solute and solvent particles
eg. NaCl Dissociation in water
H20

NaCl(s)
Na+(aq) +
Cl - (aq)
- crystal decomposition into component ions
Dissociation
When ionic solids dissociate in water, they break into ions.
Covalent compounds do not split into charged particles because they
share electrons and thus don't separate.
Ionic Dissociation Equation
what happens when ionic solid dissolves in water  ions.
ionic solid
e.g.
CuCl2(s)
 cation(s) + anion(s)
 Cu2+(aq)
+ 2 Cl1-(aq)
** in dissociation polyatomic ions are NOT broken up**
1) sodium chloride
2) magnesium bromide
3) ammonium sulfide
Individual Ion Concentration
Examples
Fe(NO3)3(s)
0.25 M
 Fe3+(aq)
+
3 NO3-1(aq)
NaOH(s)
 Na+1(aq)
+
OH-1(aq)
1.0 M
Ca3(PO4)2(s)  3 Ca+2(aq) +
0.9 M
2 PO4-3(aq)
Dilution Calculations
Concentration
M = moles
litre
or C= n
v
Examples
Calculate the molarity of a solution when 4.71g of CuCl2 is dissolved with water
for a final volume of 500 mL.
Calculate the new concentration when 500 mL of 0.0700 M CuCl2 is diluted to a
new volume of 2.00 L
If 25 mL of 0.80M NaCl and 55 mL of 0.30 M NaCl are mixed what is the final
concentration of NaCl.
Anais dissolves 60.0g of Na2CO3 into enough water to make 300.0 mL of
solution. Find the [Na+] and [CO3-2].
What mass of AlBr3 must be dissolved in 500 mL of solution to give a [Br-] =
4.50M?
Eric adds 150.0 mL of water to 50.0 mL of 0.60 M MgCl2. Find the final [Cl-].
Finding concentrations of ions in Mixtures
Note: when two solutions are mixed, each one “sees” the other as if it was water.
20.0 mL of 0.40 M CaCl2 is mixed with 80.0 mL of 0.50 M KNO3. Find the final
concentration of all 4 ions.
Mixtures with Common Ions
30.0 mL of 0.60 M Na2SO4 is mixed with 45.0 mL of 0.30 M Na3PO4. Find the
final concentration of all 3 ions.