3. Kinetic Theory of Matter Matter is made up of particles
which are in continual random motion.
4. Binding Forces between Molecules The Three States of Matter:
In order for molecules to exist in aggregates in gases, liquids and
solids Intermolecular forces must exist 4
5. What is matter? Matter is anything that has mass and takes
up space.
6. STATES OF MATTER Based upon particle arrangement Based upon
energy of particles Based upon distance between particles
7. States of matter and intermolecular forces: Gas: Molecules
in a gas attract each other, but the attractive forces are weak
compared with the thermal motion of the molecules so the molecules
spread out evenly to fill the container enclosing them, however if
a gas is cooled , the thermal motion will decrease and the gas will
first liquify and then it will solidify. Liquids: Liquids have
sufficient attractive forces to stay in an open container but they
can still flow. Properties such as viscosity and its inverse
fluidity are measures of the attractive forces in liquids. E.g.,
glycols are very viscous, while hexane flows very easily. Solids:
Solids have enough attractive forces called crystal lattice energy
that they do not even flow, e.g., magnesium stearate is a lubricant
needed to ease movement of drug powder in tableting machine.
8. Solids and the crystalline state A crystalline solid
possesses rigid and long-range order. In a crystalline solid,
atoms, molecules or ions occupy specific (predictable) positions.
An amorphous solid does not possess a well-defined arrangement and
long-range molecular order. A unit cell is the basic repeating
structural unit of a crystalline solid. lattice point At lattice
points : Atoms Molecules Ions Unit Cell 8 Unit cells in 3
dimensions
9. The crystal lattice of sodium chloride NaCl Na 9 Cl
10. Seven Basic Unit Cells The various crystal forms are divide
to basic 7 unit according to its symmetry iodine NaCl sucrose 10
Urea Iodoform Boric acid Beryl Be3Al2(SiO3)6
11. Types of Crystals 11.6
12. Characterization of crystalline materials:A- X- Ray
Diffraction:It is photographed on sensitive plate arranged behind
the crystal and by such method the structure of a crystal may be
investigated. B- Melting point and Heat of fusion The freezing
point or the melting point of a pure crystalline solid is strictly
defined as the temperature at which the pure liquid and solid exist
in equilibrium C- Polymorphism. Some substances, such as carbon or
sulfur, my exist in more than one crystalline form and are said to
be polymorphism.
13. X-Ray Diffraction X-ray are a form of electromagnetic
radiation having a wavelength of the order of interatomic
distanceoabout 1.5 A An Arrangement for Obtaining the X-ray
Diffraction Pattern of a Crystal. 13
14. Polymorphism Some elemental substance such as C and S ,may
exist in more than one crystalline form and are said to be
allotropic, which is a special case of polymorphism Polymorphism
are chemically identical, but they may have: Different stabilities
May spontaneously convert from metastable form at a temperature to
a stabile form. Different melting point, XRD pattern and different
solubility Solubility and melting point are very important in
pharmaceutical processes including dissolution and formulation.
14
15. Polymorphism and Industry/ Pharmaceutical Theobroma oil
(caco butter) Exist in 4 polymorphism Gamma form melt at 18 C Alpha
melt at 22C Beta prime form melt at 28C Stable beta form melt at
24.5 C AIDS drug ritonavir Was marked in dissolved formulation
until a previously unknown , more stable and less soluble polymorph
appeared Haloperiodal antipsychotic compound Differences in the
inter. Forces and hydrogen bonding cause the polymorphism 15
16. Polymorphism and Industry/ Pharmaceutical Cortisone acetate
Exist in at least 5 polymorph Heating, grinding , water and
suspension in water are all factors that affect the interconversion
of these different cortisone acetate forms. Tamoxifen
antiestrogenic & antineoplastic drug used for breast cancer B
form (with H bonding is more stable) than form A 16
17. Amorphous Solids An amorphous solid does not possess a
well-defined arrangement and long-range , and many synthetic
plastics) molecular order.( Ex. Glass, pitch( Amorphous substances,
as well as cubic crystal, are isotropic, that is, they exhibit
similar properties in all direction. (iso= equal) The differ from
crystalline solid in that they tend to flow and dont have definite
melting point. Crystals other than cubic are anisotropic, showing
different characteristics (electronic conductance, refractive
index(RX), crystal growth, rate of solubility ) in various
direction along the crystal. (aniso= un equal) Amorphous or
crystalline & therapeutic activity: The crystalline from of the
antibiotic novobiocin acid is poorly absorbed and has no activity,
where the amorphous form is readily absorbed and therapeutically
active, due to different dissolution rate. 17
18. PHASE CHANGES Description of Phase Change Term for Phase
Change Heat Movement During Phase Change Vaporization, Liquid to
which includes Heat goes into the gas boiling and liquid as it
vaporizes. evaporation Heat leaves the gas Gas to liquid
Condensation as it condenses. Heat goes into the Solid to gas
Sublimation solid as it sublimates.
19. Effect of Increase in Pressure on the Melting Point of Ice
and the Boiling Point of Water P T 0.006 atm 19
20. Intermolecular Forces Intermolecular forces are attractive
forces between molecules 1) ionic, 2) dipole - dipole, 3)
H-bonding, 4) London forces, 5) covalent (network solids), 6)
metallic. Intramolecular forces hold atoms together in a molecule
(ionic, polar, non-polar). Intermolecular vs Intramolecular 41 kJ
to vaporize 1 mole of water (inter) 930 kJ to break all O-H bonds
in 1 mole of water (intra) Measure of intermolecular force
Generally, intermolecular forces are much weaker than
intramolecular forces. boiling point melting point Hvap Hfus 11.2
Hsub