CHAPTER 14 LIQUIDS AND SOLIDS

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CHAPTER 14 LIQUIDS AND SOLIDS
LIQUIDS Attractive forces hold molecules close
together, although molecules can still roll around
Solid Liquid Gas
Vibrating
Rolling
Straight-Line
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PHASE CHANGES
(1) EVAPORATION If surface molecules acquire
enough kinetic energy to overcome the attractive
forces, they can escape
With liquid water in a closed container
(2) CONDENSATION Vapor molecules collide with
the surface of the liquid, lose energy, and are
captured
When these 2 processes are equal, it looks like
evaporation has stopped Really, evaporation and
condensation are occurring at equal rates
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DYNAMIC EQUILIBRIUM When 2 opposing processes
in the same system proceed at equal rates
Evaporation liquid ? vapor Condensation vapor
? liquid Equilibrium liquid ? vapor
EQUILIBRIUM VAPOR PRESSURE The pressure exerted
by a vapor when it is in equilibrium with its
liquid
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EVP depends on temperature
Temp (ºC) EVP (torr)
10 20 30
9 18 32
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BOILING
Atmospheric Pressure
A bubble is full of steam that exerts waters
EVP A bubble survives when its EVP equals
atmospheric pressure When bubbles can reach the
top the liquid is boiling
BOILING POINT The temperature at which the EVP
of the liquid equals the prevailing atmospheric
pressure
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Temp (ºC) EVP (torr)
5 10 20 30 95 100 122
7 9 18 32 634 760 1557
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HEATING CURVES
All pure substances can exist as solid, liquid,
or gas
NORMAL MELTING POINT At 1 atm pressure, the
temperature a solid turns into a liquid (also
called the NORMAL FREEZING POINT) NORMAL BOILING
POINT At 1 atm pressure, the temperature a
liquid turns into a gas
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HEAT OF FUSION The heat needed to melt a
specific amount of a solid For ice 334
J/g or 6.02 kJ/mol HEAT OF VAPORIOZATION The
heat needed to boil a specific amount of a
liquid For water 2,250 J/g or 40.6 kJ/mol
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Calculate the heat energy needed to change 10.00
g of ice at 0.0ºC to steam at 100.0ºC.
Melting Liquid Boiling
(334 J/g)
(10.00 g)
3,340 J
(4.184 J/gCº)
(10.00 g)
4,184 J
(100.0 Cº)
(2,250 J/g)
(10.00 g)
22,500 J
30,024 J
30,000 J
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SUBLIMATION A solid changing directly to a
gas Iodine (I2), Dry Ice (CO2), Mothballs
(C10H8) DEPOSITION A gas changing directly to a
solid
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SOLIDS
CRYSTALLINE SOLID A solid with a definite
particle arrangement AMORPHOUS SOLID A solid
with a random particle arrangement
Sand Glass Crystalline Amorphous
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MELTING POINTS OF SOLIDS Melting points (and
boiling points) depend on the attractive forces
BETWEEN particles (molecules, atoms, or
ions) TYPES OF SOLIDS (1) Molecular (A)
Nonpolar (B) Polar (2) Atomic (A) Nonmetalli
c Network (B) Metallic Network (3) Ionic
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(1) MOLECULAR SOLIDS
INTRAMOLECULAR FORCES Forces WITHIN a
molecule Covalent bonds They determine how
reactive a molecule is INTERMOLECULAR FORCES
Forces BETWEEN molecules They determine melting
points and boiling points
Intramolecular Forces
Intermolecular Forces
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There are two types of molecular
solids (A) NONPOLAR MOLECULAR Made of individual
nonpolar molecules Examples O2, CO2 (linear)
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Intermolecular Forces LONDON DISPERSION FORCES
(or VAN DER WAALS FORCES) The attraction of
electrons in one molecule to the nuclei in a
neighboring molecule due to the synchronizing of
electrons
d
d-
d
d-
LDFs are weak attractive forces, so nonpolar
molecular solids have low melting points LDFs
Increase in strength as the number of electrons
per molecule increase
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Although they are composed of atoms, Noble Gases
behave as nonpolar molecular matter
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(B) POLAR MOLECULAR Made of individual polar
molecules Examples HCl, SO2 (bent)
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Intermolecular Forces London Dispersion Forces,
and DIPOLE-DIPOLE ATTRACTIONS The attraction
of the positive end of one polar molecule to the
negative end of another
d-
d
d-
d
D-D Attractions are weak, so polar molecular
solids have low melting points D-D Attractions
are stronger than LDFs, so polar molecular
solids have higher melting points than nonpolar
molecular solids
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Polar molecules that have a H bonded to either N,
O, or F have a third type of attractive
force HYDROGEN BONDING An intermolecular
attraction between a H in one molecule and a N,
O, or F in a neighboring molecule
Hydrogen Bonding
Polar molecules that can H-Bond have higher
melting points than polar molecular that cannot
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H-Bonding Causes ice to be less dense than
water by forming an open crystal
lattice produces the folded shapes of
proteins holds together the strands of DNA
molecules
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(2) ATOMIC SOLIDS
There are two types of atomic
solids (A) NONMETALLIC NETWORK Made of
millions of nonmetal atoms Examples Cx
(diamond), (SiO2)x (sand) Attractive
forces Covalent bonds
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All atoms are covalently bonded together, so the
entire crystal is like one giant
molecule Covalent Bonds are strong, so
nonmetallic networks have high melting points
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(B) METALLIC NETWORK Made of millions of metal
atoms Examples Fe, Au, bronze (Cu Sn), brass
(Cu Zn) Attractive forces Metallic
Bonds

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METALLIC BONDS The attraction between metal
nuclei and the valence electrons of the millions
of atoms
Metallic Bonds are strong, so metallic networks
have high melting points
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ALLOY A solid solution of metals
SUBSTITUTIONAL ALLOY Brass
INTERSTITIAL ALLOY Steel
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(3) IONIC SOLIDS
Made of millions of positive and negative
ions Examples NaCl, CuSO4 Attractive
forces Ionic Bonds
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-


-
-

-
Ionic Bonds are strong, so ionic substances have
high melting points
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Substance MP (ºC) Substance Type Attractive Forces
H2 O2 Ar HCl HBr NH3 H2O NaCl MgF2 Fe W (SiO2)x Cx

-259 -218 -189 -114 -89 -78 0 801 1266 1
535 3410 1723 3550
Nonpolar Molecular Polar Molecular Ionic
Metallic Network Nonmetallic Network
LDF LDF, D-D LDF, D-D, H-B Ionic
Bonds Metallic Bonds Covalent Bonds
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ELECTRICAL CONDUCTION
ELECTRICIAL CONDUCTION The movement of charges
particles (electrons or ions) through a material
Conductors Metallic networks Electrons can
move throughout the metallic bonds Nonconductors
Molecular solids or Nonmetallic
networks Electrons are locked in covalent
bonds Ionic solids Ions are locked in position
as a solid, BUT melted or dissolved in water,
the ions can move and the ionic material
conducts
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REVIEW FOR TEST
Pressure (mm Hg, torr, atm) Temperature (ºC,
K) Standard Temperature and Pressure
(STP) Boyles Law, Charles Law, Avogadros
Law Char-Boyled Law Ideal Gas Law Partial
Pressure Water Vapor Pressure Pressure of Gases
Collected in Lab Over Mercury Over Water Gas
Volumes in Chemical Reactions
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REVIEW FOR TEST
Dynamic Equilibrium Melting, Boiling,
Sublimation Heat of Fusion, Heat of Vaporization,
Specific Heat Capacity Heating Curves, Heat
Calculations Crystalline, Amorphous
Solids Intramolecular Forces, Intermolecular
Forces London Dispersion Forces, Dipole-Dipole
Interactions, Hydrogen Bonding Attractive Forces,
MPs, Conductivity of Molecular Solids
(Nonpolar Molecular and Polar Molecular) Atomic
Solids (Nonmetallic Networks and Metallic
Networks) Ionic Solids Alloys (Substitutional,
Interstitial)
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