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Types of Types of SolidsSolids
Chap. 13: Day 4b
2Metallic and Ionic Metallic and Ionic SolidsSolids
Sections 13.6-8Sections 13.6-8
Metallic and Ionic Metallic and Ionic SolidsSolids
Sections 13.6-8Sections 13.6-8
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Properties of SolidsProperties of Solids
1. 1. Molecules, atoms or ions locked into a CRYSTAL LATTICE
2. Particles are CLOSE together
3. STRONG IM forces
4. Highly ordered, rigid, incompressible
ZnS, zinc sulfideZnS, zinc sulfide
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Types of SolidsTypes of SolidsTable 13.6Table 13.6
TYPETYPE FORCE Properties . FORCE Properties .
Ionic Ionic Ionic Ionic Hard, brittle, High MP Hard, brittle, High MP
poor conductorpoor conductor
Metallic Electrostatic Metallic Electrostatic Malleable, Range of MP Malleable, Range of MP
good conductorgood conductor
MolecularMolecular Dipole Soft, Low of MP Dipole Soft, Low of MP
Ind. Dipole poor conductorInd. Dipole poor conductor
NetworkNetwork Extended Extended Range of MP & hardnessRange of MP & hardness
covalent covalent poor conductorpoor conductor
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Network SolidsNetwork Solids
DiamondDiamond
GraphiteGraphite
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Network SolidsNetwork Solids
A comparison of diamond (pure carbon) A comparison of diamond (pure carbon) with silicon.with silicon.
8Atom Packing in Unit Atom Packing in Unit CellsCells
Assume atoms are hard spheres and that crystals are built by PACKING of these spheres as efficiently as possible.
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PROPERTIES
OF LIQUIDS
Chap. 13: Day 4a
Intermolecular Forces
The forces BETWEEN molecules. Holds the molecules together. At a set temperature:
What phase has the strongest force? Solids
What phase has the weakest forces? Gases (vapor)
Viscosity•the resistance of a fluid to flow
Thick fluids have high viscosity
Liquid Properties Surface Tension- Ability of liquid molecules to
hold on to each other. Apparent “skin” affect Ex. Over filling a liquid in a glass with out the
liquid spilling
Hg
Liquid Properties
Capillary Rise- the tendency of a liquid to rise in a small diameter tube due to the surface tension of the liquid.
Vapor Pressure
The pressure exerted by a vapor in equilibrium with its liquid state.
The pressure at which liquid changes to vapor
Liquids with high vapor pressures turn into vapors very easily. (Volatile)
Ex. Gasoline, perfume
Once equilibrium is reached, the vapor particles will begin to condense back to a liquid
Boiling Point
The temperature at which the vapor pressure of the liquid equals the atmospheric pressure
The entire liquid is changing state, not just the surface.
Water boils at 1000C
at standard P
Vapor Pressure vs Temperature
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TWO ways to change PHASE
•Temperature
Pressure
PHASE CHANGES:
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Almeltingpoints
SOLID
LIQUID
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Boiling points: Liquid to Vapor
Water
LIQUID
GAS
27Phase DiagramsPhase Diagrams
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TRANSITIONS TRANSITIONS BETWEEN BETWEEN PHASESPHASESSection 13.10Section 13.10
Lines connect all conditions of T and P where EQUILIBRIUM exists between the phases on either side of the line.
(At equilibrium particles move from liquid to gas as fast as they move from gas to liquid, for example.)
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Phase Equilibria — WaterPhase Equilibria — Water
Solid-liquidSolid-liquid
Gas-Gas-LiquidLiquid
Gas-Gas-SolidSolid
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Triple Point Triple Point — Water— Water
At the At the TRIPLE POINTTRIPLE POINT all all three phases are in three phases are in equilibrium.equilibrium.
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Phases Phases Diagrams—Diagrams—
Important Points Important Points for Waterfor Water
T(˚C)T(˚C) P(mmHg)P(mmHg)
Normal boil point Normal boil point 100100 760760
Normal freeze pointNormal freeze point 00 760760
Triple point Triple point 0.00980.0098 4.58 4.58
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Critical T and PCritical T and P
.
LIQUID
GAS
Pcritical
Hig
h P
ress
ure
High Temperature
Tcritical
Note that linegoes straight up
Above critical T Above critical T no liquid exists no liquid exists no matter how no matter how high the high the pressure.pressure.
Above critical T Above critical T no liquid exists no liquid exists no matter how no matter how high the high the pressure.pressure.
As P and T increase, you finally reach the
CRITICAL T and P
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Critical T and PCritical T and P
TTcc((ooC) PC) Pcc(atm) M ((atm) M (g/molg/mol))
HH22OO 374 374 218 (18) P 218 (18) P
Freon-12Freon-12 112112 41 (121) NP 41 (121) NP
(CCl(CCl22FF22))
COCO22 31 31 73 (44) NP 73 (44) NP
CHCH44 -82 -82 46 (16) NP 46 (16) NP
Notice that TNotice that Tcc and P and Pcc depend on depend on
intermolecular forces.intermolecular forces.
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37Phase Diagram for Water
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Solid-Liquid EquilibriaSolid-Liquid Equilibria
Raising the pressure at constant T causes water to melt.
The NEGATIVE SLOPE of the S/L line is unique to H2O. Almost everything else has positive slope.
SolidH2O
LiquidH2O
P
T
760mmHg
0 ÞC
Normalfreezingpoint
LIQUID H2OICEfavored atlow P
favored athigh P
LIQUID H2OICEfavored atlow P
favored athigh P
INTERMOLECULAR FORCES
STRONG Forces lead to….
Nonvolatile Substances
High boiling points Low evaporation
rates Low vapor P at
room temperature
WEAK Forces lead to..
Volatile substances
Low boiling points High evaporation
rates High vapor P at
room temperature