1. UNIT VIII PPT #1
Solution Chemistry

2. IX.1 SOLUTIONS AND SOLUBILITY
Definitions:
Solution:
a homogeneous mixture
Solvent:
the component in a mixture in the greater quantity
Solute:
the component in a mixture in the lesser quantity

3. IX.1 SOLUTIONS AND SOLUBILITY
Saturated:
a solution is said to be saturated if the solvent has dissolved as much of the solute as possible
Unsaturated:
a solution is unsaturated if it can dissolve more of the solute being added
Solubility:
The maximum amount of the solute which can be dissolved in a given amount of solvent at a given temperature.

4. IX.1 SOLUTIONS AND SOLUBILITY

5. IX.1 SOLUTIONS AND SOLUBILITY

6. IX.2 THE CONDUCTIVITY OF AQUEOUS SOLUTIONS
A conducting solution contains ions; the greater the concentration of ions, the greater the conductivity.
A compound made up of a METAL and NONMETAL is IONIC, and forms a conducting solution in water.
A substance made up of a NONMETAL and a NONMETAL is COVALENT, and will NOT form a conducting solution in water.

7. IX.2 THE CONDUCTIVITY OF AQUEOUS SOLUTIONS
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. 

8. IX.2 THE CONDUCTIVITY OF AQUEOUS SOLUTIONS
Compounds whose formulae start with a CARBON ATOM are usually ORGANIC and normally DO NOT form a conducting solution in water.
ACIDS and BASES form conducting solutions in water.

9. IX.2 THE CONDUCTIVITY OF AQUEOUS SOLUTIONS
**TO CONDUCT or NOT CONDUCT??? that is the question.....
CONDUCT DOESN’T CONDUCT
ionic - solid
acidic - covalent
basic - starts with C
CH3COOH (exception)
Hebden p. 198 # 6-8

10. Dry Lab
Work through the dry lab handout.

11. IX.3 MOLECULAR POLARITY Van der Waals Forces: THREE main types:
DIPOLE-DIPOLE FORCES
LONDON FORCES
HYDROGEN BONDING

12. IX.3 MOLECULAR POLARITY A. DIPOLE-DIPOLE FORCES Dipole:
*a permanent dipole results from atoms with different ELECTRONEGATIVITY!
Dipole-Dipole Forces:

13. IX.3 MOLECULAR POLARITY Polar: Note the asymmetry
Molecule must be asymmetrical
to be Polar and must have at least
one dipole
Nonpolar:
Can have at least one dipole but
are symmetrical , so they are
nonpolar molecules

14. IX.3 MOLECULAR POLARITY
Ex: Which of the following are expected to be polar and which are expected to be nonpolar??
nonpolar = symmetrical polar = assymetrical
(if one end of the molecule differs from the other)
Methane Hydrogen fluoride

15. IX.3 MOLECULAR POLARITY B. LONDON FORCES London Forces:
*if a permanent dipole is ABSENT….LONDON FORCES!

16. Intramolecular Intermolecular
IX.3 MOLECULAR POLARITY
IONIC BOND DIPOLE – DIPOLE ==LONDON FORCE
Intramolecular Intermolecular
*the attraction between polar molecules is much less than the attraction between ions
*polar molecules have a higher boiling temp then nonpolar

17. IX.3 MOLECULAR POLARITY C. HYDROGEN BONDING
Hydrogen Bond: strong dipole – dipole attraction between molecules containing a H – N, H – O, or H – F
 *intermolecular bond
*strongest van der Waals bonds – but still weaker than covalent and ionic

18. IX.3 MOLECULAR POLARITY
Hebden p. 199 #9, p. 202 # 11-12, p. 203 # 13-16

19. IX.4 POLAR AND NONPOLAR SOLVENTS
BOND TYPE
WHAT TO LOOK FOR...
INTRAMOLECULAR BONDS:
IONIC BOND
Made up of metal and nonmetal (or recognizable ions)
COVALENT BOND
Made up of nonmetal and nonmetal
INTERMOLECULAR BONDS:
HYDROGEN BOND
Look for HF or any molecule having OH or NH in its formula
DIPOLE-DIPOLE FORCE
Look for an asymmetric molecule
LONDON FORCE
Always present

20. IX.4 POLAR AND NONPOLAR SOLVENTS
Common solvents: p.204
water
methanol
ethanol
benzene
ethoxyethane
acetone
acetic acid
chloroform
carbon tetrachloride
heptane
liquid ammonia

21. IX.4 POLAR AND NONPOLAR SOLVENTS
“LIKE DISSOLVES LIKE”
POLAR dissolves POLAR
IONIC
NONPOLAR
NONPOLAR dissolves NONPOLAR

22. IX.4 POLAR AND NONPOLAR SOLVENTS
Dissolving Process – 3 ATTRACTIONS:
attraction of solvent molecule to surrounding solvent molecules
attraction of solvent molecule to particles of solute
attraction of one solute particle to other solute particles
*when no CHARGE ==== no attraction

23. IX.4 POLAR AND NONPOLAR SOLVENTS

24. IX.4 POLAR AND NONPOLAR SOLVENTS
POLAR and IONIC solutes have low solubilities in nonpolar solvents.
POLAR and IONIC solutes tend to dissolve in polar solvents.

25. IX.4 POLAR AND NONPOLAR SOLVENTS
NON POLAR solutes tend to be soluble in nonpolar solvents.
*only attracted to solute particles by London Forces
NONPOLAR substances tend to have at most a low solubility in polar solvents.

26. IX.4 POLAR AND NONPOLAR SOLVENTS
**WATER is one of the most polar solvents known and tends to dissolve both polar and ionic solutes.
Hebden p. 207 # 18-22, p. 208 # 23-27

27. IX.5 THE NATURE OF SOLUTIONS OF IONS
The formation of a solution depends on the ability of the solute to dissolve in the solvent.
SOLVATION:
IONIC SOLID:
MOLECULAR SOLID:

28. IX.5 THE NATURE OF SOLUTIONS OF IONS

29. IX.5 THE NATURE OF SOLUTIONS OF IONS
Ex: NaCl dissolving in water

30. IX.5 THE NATURE OF SOLUTIONS OF IONS
DISSOCIATION:
ex: NaCl > Na Cl

31. IX.5 THE NATURE OF SOLUTIONS OF IONS
IONIZATION:
ex: CH3COOH + H2O > CH3COO- + H3O +
Hebden p. 210 # 28 & 29