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UNIT IX
Solution Chemistry
Lesson #1
INTRODUCTION
Solution Chemistry is the study of chemical reactions that
occur in solutions…
Reactions in solutions are chemists’ favourite type of
reactions…because of how easy and convenient they are.
Compare to:
Reactions in the gas phase are complicated need special
containers (air-tight)
Solid reactions  very slow or do not occur at all
LET’S REMEMBER SOME DEFINITIONS
Solution: is a homogeneous mixture
Solvent: the component in the solution that exists
in the ___________ amount.
Solute: the component in the solution that exists in
the ___________ amount.
SOLUTIONS AND SOLUBILITY

Saturated solution:

Unsaturated solution:

Solubility: max. amount of a solute dissolved in
a given amount of solvent at a constant
temperature.
Saturated Vs Unsaturated
SOLUTIONS AND CONDUCTIVITY

Do all solutions conduct electricity?

How do we know?
Requirements to conduct electricity
Experiments tell us that you need…
Electrical charge to be transferred in the
solution in order to produce electricity.
IONS carry electrical charge!
Requirements to conduct electricity
IONS carry electrical charge!
Therefore, Ionic compounds can conduct
electricity
NaCl(aq)
NaCl(s)
Can covalent compounds conduct electricity?
CS
THE CONDUCTIVITY OF AQUEOUS
SOLUTIONS



A conducting solution contains ions; the greater the
concentration of ions, _____________the conductivity.
A compound made up of a METAL and NONMETAL is
IONIC, and forms a conducting solution in water
because it breaks into ________
A substance made up of a NONMETAL and a
NONMETAL is COVALENT, and will NOT form a
conducting solution in water because it stays as a
molecular compound.
NaCl (Ionic) in
water
The "+" and "-" ions are now free to move around. The "+" ions would be
attracted to a negative electrode and the "-" ions would be attracted to a
positive electrode. In this way, the ionic solution conducts a current.
What else can conduct electricity??
ACIDS and BASES form conducting
solutions in water.
 Why?


Because they can break into ions!

HCl(aq)

NaOH(aq)

HCl(s)
What else can conduct electricity??
ACIDS and BASES form conducting solutions in
water.
1- Think of acids as any compounds that starts
with H
2- Think of bases as any compounds that end with
OH

Exception; if a compound starts with Carbon and
ends with OH. It is an alcohol, not a base and can’t
conduct electricity.
Ex: CH3OH (can’t conduct electricity)
What else can conduct electricity??
Metals in all phases can conduct electricity 
Examples: Na(l), Cu(aq), Na(s)
So what can’t conduct electricity??
1) Non-metals
2) Covalent compounds (metal + non-metal)
3) Organic compounds(usually start with
Carbon-C- and contain hydrogens)
Ex: CH3OH, C14H10
*CH3COOH (exception)- can conduct.
4) Solids !!!!!!!!!!! (except if they’re metals)
TO CONDUCT or NOT TO CONDUCT??? This is the
question.....
CONDUCT
Metals
ionic
Acids(solutions)
Bases(solutions)
*CH3COOH (exception)
DOESN’T CONDUCT
non metals
solid
covalent
* organic compounds
http://www.youtube.com/watch?v=UHYWIM8AbPE
THINK ABOUT THIS
For solutions to form, and to mix chemical
compounds together when adding a solute to a
solvent to make a solution…bonds need to break
and new bonds need to form!
So, we need to remember the intermolecular
forces that hold molecules together….
Back to forces between molecules…
Van der Waals Forces:
THREE main types:
A. DIPOLE-DIPOLE
B. LONDON
FORCES
FORCES
C. HYDROGEN
BONDING
All are caused by dipoles!
A.
A. DIPOLE-DIPOLE FORCES
Caused by dipoles
Dipole: A temporary separation of charges, where more
electrons are found on one side on the atom than the
other side.

Dipole-Dipole Forces: a permanent dipole results
from atoms with different ELECTRONEGATIVITY!
DIPOLE-DIPOLE FORCES
Ex:
HCl
H 2O
B. LONDON FORCES

London Forces:
LONDON FORCES exist for everything!!!
London forces’ strength increases as the # of
electrons is increased.
Ex: Does He or Xe have a stronger london forces
bond?
C. HYDROGEN BONDING
Hydrogen Bond: strong dipole – dipole attraction
between molecules containing a H – N, H – O, or H – F
bond
(because N,F and O are highly electronegative)



*intermolecular bond (between molecules)
*strongest van der Waals bonds – but still weaker than
covalent and ionic
C. HYDROGEN BONDING

Hydrogen Bond: strong dipole – dipole attraction
between molecules containing a H – N, H – O, or H – F
Ex:
NH3 and NH3
H2O and H2O
Hint: Look for HF or any molecule having OH or NH in its formula
COMPARING STRENGTHS OF BONDS
IONIC BOND DIPOLE – DIPOLE ~ LONDON
FORCE
Intramolecular
Intermolecular
Ionic bonds will always be stronger than any
intermolecular bond.
Remember, London forces strength increases with the
increased number of electrons.
EXPLAIN THIS:
Boiling temperatures:
ICl = 97 C (70 electrons)
Br2 = 59 C (70 electrons)
HOMEWORK
Page 198,199
Questions 6,7
Question 8 (do a,c,e, etc)
Question 9
Page 202, 203, 204
Question 11 and Question 12
Question 14 and Question 16