liquids and solids ap chem unit 10. sections intermolecular forces liquid state solid structures...
TRANSCRIPT
![Page 1: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/1.jpg)
Liquids and Solids
AP Chem Unit 10
![Page 2: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/2.jpg)
SectionsIntermolecular Forces
Liquid state
Solid Structures
Metal Structures
Carbon and Silicon Networks
![Page 3: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/3.jpg)
SectionsMolecular Solids
Ionic Solids
Vapor pressure and State Change
Phase Diagrams
![Page 4: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/4.jpg)
States of Matter
When considering the three states of matter, properties of gases are strikingly different than solids and liquids. Liquids and solids share many similar characteristics
compressibility
density
intermolecular forces
![Page 5: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/5.jpg)
States of Matter
H2O(s)H2O(l) ΔH°fus = 6.02 kj/mol
H2O(l)H2O(g) ΔH°vap = 40.7 kj/mol
Water densities:25°C and 1atm
.99707g/cm3
25°C and 1065 atm 1.046g/cm3
400°C and 1atm 3.26x10-4 g/cm3
400°C and 242 atm .157g/cm3
![Page 6: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/6.jpg)
Intermolecular Forces
10.1
![Page 7: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/7.jpg)
Intermolecular Forces
Electrons shared within the molecule are called intramolecular bonding.
In the condensed states of matter the attraction between molecules are called intermolecular forces.
![Page 8: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/8.jpg)
Intermolecular Forces
It is important to realize that when a molecule changes state, the molecule stays intact. The changes in state are due to the change in forces surrounding the molecule not from changes within the molecule.
40.7kj needed to vaporize water934kj to break the O-H bond
![Page 9: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/9.jpg)
Dipole–Dipole Forces
Dipole-dipole forces occur when polar molecule (molecules with dipole moments) electrostatically attract each other by lining up the positive and negative ends of the dipoles.
Dipole-dipole forces are about 1% as strong as a covalent or ionic bond and rapidly become weaker when distances between the dipoles increases. The distances in a gas make these attractions relatively unimportant
![Page 10: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/10.jpg)
Dipole-Dipole Forces
In a condensed state, molecules line up dipoles to minimize repulsions and maximize attractions.
![Page 11: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/11.jpg)
Dipole-Dipole Forces
Some dipole-dipole forces are unusually strong. These usually form between H and another very electronegative atom.
These are stronger due to the high polarity of the bond and the closeness of the dipoles between the atoms.These strong attractions have a
strong impact on melting points and boiling points.
![Page 12: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/12.jpg)
Boiling Points of Covalent Hydrides
![Page 13: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/13.jpg)
Hydrogen bonds
Hydrogen bonds are the strongest in the smallest and lightest of the covalent molecules. This is primarily due to two factors:
large difference in electronegativities
small size of the atoms allows for close dipole interactions.
![Page 14: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/14.jpg)
Hydrogen bonds
![Page 15: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/15.jpg)
Hydrogen Bonds and Organics
Methanol (CH3OH) and ethanol (CH3CH2OH) have much higher boiling points than would be expected from their molar masses because of the O-H bonds that produce hydrogen bonding.
![Page 16: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/16.jpg)
London Dispersion Forces
Even without dipoles, molecules exert forces on each other.
The forces that exist among noble gas atoms and nonpolar molecules are called London dispersion forces.
![Page 17: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/17.jpg)
London Dispersion Forces
Usually it is assumed that electron dispersion is uniform throughout the molecule, but this is not always the case.
Since the movements of the electrons around the nucleus are somewhat random, a momentary nonsymmetrical electron distribution can develop that creates a temporary dipolar arrangement of charge.
![Page 18: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/18.jpg)
London Dispersion Forces
This temporary change in polarity can, in turn, temporarily change the distribution of the neighboring molecule.
This phenomenon leads to an inter-atomic attraction that is relatively weak and short-lived, but can be significant in larger atoms at lower temperatures.larger atoms have more electrons and
increases the probability of a temporary dipole.
![Page 19: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/19.jpg)
London Dispersion Forces
![Page 20: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/20.jpg)
London Dispersion Forces
Polarizability is the ease at which an electron cloud can be distorted into a temporary dipole.
large atoms have a larger polarizability than smaller atoms
This also applies to molecules like H2, CH4, CCl4 and CO2; smaller molecules, but nonpolar.
![Page 21: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/21.jpg)
The Liquid State10.2
![Page 22: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/22.jpg)
Liquid Characteristics
lack of rigidity
low compressibility
high density
rounded droplets
capillary action
viscosity
![Page 23: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/23.jpg)
Rounded Droplets
Occur due to the intermolecular forces of the liquid. The liquid molecules are subject to attraction from the side and from below, so liquid tends to form a shape with the minimum surface area – sphere.
The resistance of a liquid to increase surface area is from the energy that it takes to overcome intermolecular forces. This resistance is called surface tension.
![Page 24: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/24.jpg)
Rounded Droplets
Molecules that are polar and have stronger intermolecular forces have stronger surface tensions.
![Page 25: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/25.jpg)
Surface Tension
![Page 26: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/26.jpg)
Capillary Action
Capillary action is the spontaneous rising of a liquid in a narrow tube. This action is due to two forcescohesive forces- the intermolecular
forces among the molecules.adhesive forces – the attractive
forces between the liquid and the container.
![Page 27: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/27.jpg)
Adhesive forces
Adhesive forces happen when bonds within the container have polar bonds
For example: glass has O atoms that carry a partial negative charge that attracts the partial positive charge of the hydrogen in water. This balance between the strong cohesive forces and the strong adhesive forces produce a meniscus.
![Page 28: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/28.jpg)
Adhesive forces
A nonpolar substance, such as mercury, has a convex meniscus because the cohesive forces are stronger than the adhesive forces.
![Page 29: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/29.jpg)
Meniscus: Water vs. Mercury
![Page 30: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/30.jpg)
ViscosityViscosity is a fluids resistance to flow.
liquids with strong cohesive forces tend to be highly viscous. Example: glycerol is highly viscous
because of its ability to create hydrogen bonds.
![Page 31: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/31.jpg)
Viscosity
Molecular complexity also can affect viscosity because they can become entangled in each other.Example: Gasoline has carbon chains
from 3-8C long and is nonviscous. Grease is 20-25C long and is very viscous.
![Page 32: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/32.jpg)
Introduction to Structures and Types of
Solids10.3
![Page 33: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/33.jpg)
Types of Solids
Crystalline solids
Amorphous solids
![Page 34: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/34.jpg)
Crystalline Solids
Crystalline solids have a regular arrangement of components at a microscopic level and produce beautiful, characteristic shapes of crystals:
![Page 35: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/35.jpg)
Crystalline Solids
The positions of components are usually represented by a lattice.
lattice is a three dimensional system of units repeating in a pattern. The smallest repeating unit of the lattice is called the unit cell.
![Page 36: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/36.jpg)
Three types of Crystalline Solids
![Page 37: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/37.jpg)
Amorphous Solids
Amorphous solids have considerable disorder in their structures.
Example: Common glass looks like a solution frozen in place. It has a rigid shape but a great deal of disorder within its structure.
![Page 38: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/38.jpg)
X-ray Analysis of Solids
The structures of crystalline solids are commonly determine by X-ray diffraction.
This type of diffraction occurs when beams of light are scattered as they go through spaces between substances. Light scatters when the size of the spaces are similar to the wavelength of light.
![Page 39: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/39.jpg)
X-ray Analysis of Solids
![Page 40: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/40.jpg)
X-ray Analysis of Solids
A single wavelength is directed at the crystal and a diffraction pattern is obtained. The diffraction pattern is a series of light and dark areas on a photographic plate from constructive and destructive interference from waves of light.
The diffraction pattern can then be used to determine the interatomic spacings.
![Page 41: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/41.jpg)
X-ray Analysis of Solids
A diffractometer is a computer-controlled instrument used for carrying out the X-ray analysis of crystalsIt rotates the crystal with respect to
the X-ray beam and collects the data produced by the scattering. The techniques have been refined to the point that very complex structures can be determined, such as large biological enzymes.
![Page 42: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/42.jpg)
X-ray Analysis of Solids
The Bragg equation combines trigonometry and physics to determine the atomic spaces between crystals:
nλ = 2d sin θ
d is the distance between atoms and θ is the angle of incidence and reflection of the light. n is an integer, most commonly 1. (n is usually given)
![Page 43: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/43.jpg)
X-ray Analysis of Solids
![Page 44: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/44.jpg)
Example Problem
X-rays of wavelength 1.54 Â were used to analyze an aluminum crystal. A reflection was produced at θ = 19.3°. Assuming n=1, calculate the distance d between the planes of atoms producing this reflection
2.33 Á
![Page 45: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/45.jpg)
Types of Solids
Ionic solidsionic solids are made of ions
Molecular solidsMolecular solids have small units of
covalently bonded molecules.
Atomic solidsAtomic solids are made of elements
such as carbon (graphite, diamond and the fullerenes), boron, silicon, and all metals.
![Page 46: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/46.jpg)
Fullerenes
![Page 47: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/47.jpg)
Types of Solids
![Page 48: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/48.jpg)
Atomic SolidsAtomic solids are broken down into
subgroups depending on the bond that exists in the solid:
Metallic solidsHas delocalized nondirectional covalent
bonding.
Network solidsatoms bond with strong directional
covalent bonding that lead to giant molecules and networks
![Page 49: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/49.jpg)
Atomic SolidsGroup 8A solids
noble gases are attracted to each other with London dispersion forces.
![Page 50: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/50.jpg)
Classification of Solids
![Page 51: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/51.jpg)
Structure and Bonding in Metals
10.4
![Page 52: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/52.jpg)
Metal Characteristics
Most of the properties that we see in metals is due to the nondirectional covalent bonding found in metal crystals.
High thermal conductivity
Electrical conductivity
Malleability
Ductility
![Page 53: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/53.jpg)
Metallic Crystals
Metallic crystals can be pictured as containing spherical atoms packed together that can be bonded to each other equally in all directions.
This arrangement is called closest packing.
![Page 54: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/54.jpg)
Closest Packing
The spheres pack in layers. Each sphere is surrounded by six others. These layers do not lie directly over those in the first layer, instead they fill the indentations of the layer below. The third layer is in the same position as the first. This is called aba arrangement.
![Page 55: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/55.jpg)
Closest Packing
The aba arrangement has the hexagonal unit cell and the resulting structure is called the hexagonal closest packed (hcp) structure.
The abc arrangement has a face-centered cubic unit cell and the resulting structure is called the cubic closest packed (ccp) structure. This has a repeating vertical placement every fourth layer.
![Page 56: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/56.jpg)
Closest Packing
![Page 57: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/57.jpg)
Closest Packing: Hexagonal
![Page 58: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/58.jpg)
Closest Packed: Cubic
![Page 59: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/59.jpg)
Closest Packing
Knowing the net number of atoms in a particular unit cell is important for many applications involving solids.
![Page 60: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/60.jpg)
Closest Packing
Example: A face centered cube (unit cell) is defined by the centers of the spheres on the cube’s corners. Therefore 8 cubes share a given corner sphere, so 1/8 of this sphere lies inside the unit cell. (8 corners x 1/8 sphere = 1sphere). The sphere at the center of each face is shared by two cubes. (6 faces x ½ sphere = 3 spheres). The total number of spheres for a face centered cube is 4.
![Page 61: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/61.jpg)
Closest Packing
Face – Centered Cubic Unit Cell
![Page 62: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/62.jpg)
Cubic Substances
Metals that form cubic closest packed solids are:
aluminum
iron
copper
cobalt
nickel
![Page 63: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/63.jpg)
Hexagonal Substances
Metals that form hexagonal closest packed solids are:
magnesium
zinc
![Page 64: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/64.jpg)
Other Metal Solids
Calcium and certain other metals can crystallize in either cubic or hexagonal solids.
Some metals, including many alkali metals, have structures that are characterized by a body-centered cubic (bcc) unit cell. In this structure, each sphere has 8 neighbors.
![Page 65: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/65.jpg)
Example Problem
Silver crystallizes in a cubic closest packed structure. The radius of a silver atom is 144pm. Calculate the density of solid silver?
10.6 g/cm3
![Page 66: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/66.jpg)
Bonding Models for Metals
In order to determine bonding for metals, one must account for the typical properties: durable, high melting point, malleable, ductile, and efficient in uniform conduction of heat and electricity in all directions.
These characteristics indicate that the bonds are strong and nondirectional. In other words, it is not easy to separate metal atoms but easy to move them.
![Page 67: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/67.jpg)
Electron Sea Model
Metal cations ‘swim’ in a sea of valence electrons that are mobile and shared.
This accounts for conduction and malleability and ductility.
![Page 68: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/68.jpg)
Electron Sea Model
![Page 69: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/69.jpg)
Band Model (MO Model)
In this model, the electrons are assumed to travel around the metal crystal in molecular orbitals formed from the valence atomic orbitals of the metal atoms.
When metals atoms interact, the large number of resulting molecular orbitals become more closely spaced and finally form a virtual continuum of levels, called bands.
![Page 70: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/70.jpg)
Band Model (MO Model)
![Page 71: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/71.jpg)
Band Model
The electrons in partially filled MO’s are mobile. These conduction electrons are free to travel throughout the metal crystal. The MO occupied by these conducting electrons are called conduction bands.
![Page 72: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/72.jpg)
Band Model
![Page 73: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/73.jpg)
Metal Alloys
An alloy is best defined as a substance that contains a mixture of elements and has metallic properties. There are two types of alloys:
Substitutional alloy– some of the host metal atoms are replaced by other metal atoms of similar size.
Interstitial alloy – is formed when some of the interstices (holes) in the closest packed lattice are occupied by smaller atoms.
![Page 74: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/74.jpg)
Metal Alloys
![Page 75: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/75.jpg)
Substitutional Alloys
Example: brass: 1/3 of copper metal atoms are replaced by zinc atoms
Sterling silver- 93% silver and 7% copper.
Pewter- 85% tin, 7% copper, 6% bismuth and 2% antimony.
Plumbers solder – 95% tin and 5% antimony
![Page 76: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/76.jpg)
Interstitial Alloy
Example: Steel contains carbon atoms in the holes of an iron crystal. The presence of the interstitial atoms changes the properties of the host metal. Iron is relatively soft, ductile and malleable, but when carbon (which forms directional bonds), is introduced into the crystal, it makes the iron bonds stronger and less ductile.
![Page 77: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/77.jpg)
Interstitial Alloy
The amount of carbon directly affects the properties of steel:
Mild steels- contains less than .2% carbon: nails chains and cables.
Medium steels- contain .2-.6% carbon: rails and structural steel
High-carbon steel – .6-1.5% carbon: springs, tools and cutlery.
![Page 78: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/78.jpg)
Mixed AlloysSome steels contain elements in addition
to iron and carbon. These are called alloy steels and are viewed as being mixed interstitial and substitutional alloys.
Bicycle frames are usually constructed from a wide variety of alloy steels.
![Page 79: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/79.jpg)
Carbon and Silicon Network Atomic Solids
10.5
![Page 80: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/80.jpg)
Network Solids
Many atomic solids contain strong directional covalent bonds to form a solid that might be viewed as a “giant molecule.” These materials are typically brittle and do not efficiently conduct heat and electricity. Two examples of these network solids are carbon and silicon.
![Page 81: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/81.jpg)
CarbonTwo most common forms of carbon are
diamond and graphite. They are typical network solids.
Diamond is the hardest naturally occurring substance.
Graphite is slippery, black and a conductor.
![Page 82: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/82.jpg)
DiamondEach carbon is surrounded by a tetrahedral
arrangement of other carbon atoms to form a large molecule. Diamond is an insulator not a conductor. Each carbon is sp3 hybridized with localized bonding and therefore does not conduct.
Diamonds are often used for industrial cutting implements.
The application of 150,000 atm at 2800°C can break graphite bonds and rearrangement into a diamond structure.
![Page 83: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/83.jpg)
Graphite
The structure of graphite is based on layers of carbon atoms arranged in fused 6 C rings. The unhybridized p orbitals allow for delocalized electrons and therefore conductivity.
Graphite is used as a industrial lubricant. Because graphite has strong bonds within the layers and weak bonding between the layer, the layers slide past one another readily.
![Page 84: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/84.jpg)
Carbon
![Page 85: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/85.jpg)
Carbon: Graphite layers
![Page 86: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/86.jpg)
Silicon
Silicon is an important constituent of the compounds that make up the earth’s crust. Silicon is to geology what carbon is to biology and is fundamental to most rocks, sands and soils found in the earth’s crust.
Carbon compounds typically have long strings of C-C bonds
Silicon compounds typically involve chains of Si-O bonds.
![Page 87: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/87.jpg)
SilicaThe fundamental
silicon-oxygen compound is silica, which has the empirical formula SiO2. The structure that is formed is based on a network of SiO4 tetrahedra with shared oxygen atoms rather than smaller SiO2 units.
![Page 88: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/88.jpg)
SilicaWhen silica is heated
above its melting point (1600°c) and cooled rapidly, an amorphous solid called glass results. Glass has a lot of disorder as opposed to the crystalline nature of quartz. Glass, also homogeneous, more closely resembles a very viscous solution than it does a crystalline solid.
![Page 89: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/89.jpg)
GlassThe properties of glass can vary greatly
depending on the additives.
Common glass results when substances like Na2CO3 are added to the silica melt.
B2O3 produce borosilicate glass which does not expand and contract during large temperature changes. (Pyrex)
K2O produces especially hard glass that can be ground into shapes for lenses and contacts.
![Page 90: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/90.jpg)
Glass
![Page 91: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/91.jpg)
Silicates
Compounds closely related to silica and found in most rocks, soils and clays are the silicates. Like silica, the silicates are based on interconnected SiO4 tetrahedra, but instead of a O/Si ratio of 2:1, the ratio is typically higher. This higher ratio tends to make silicon-oxygen anions.
![Page 92: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/92.jpg)
Silicates
![Page 93: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/93.jpg)
Silicates
Ceramics are typically made from clays (which contain silicates) and hardened by firing at high temperatures. They tend to be strong, brittle and heat and chemical resistant.
Ceramic is heterogeneous and contain two phases: minute crystals of silicates that are suspended in a glassy cement.
![Page 94: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/94.jpg)
ClaysClay comes from the
weathering of feldspar, an Aluminosilicate (Na2O/K2OAl2O36SiO2). This weathering produces kaolinite, that consists of tiny thin platelets of Al2Si2O5(OH)4. When dry these platelets cling together and lock into place; when wet they can slide over one another. During firing, these platelets bind and form a glass.
![Page 95: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/95.jpg)
CeramicsCeramics constitute one of the most
important classes of ‘high-tech” materials. Their stability at high temperatures and resistance to corrosion, make them an obvious choice for constructing jet and car engines.
Organoceramics are taking form by the addition of organic polymers to ceramics. This reduces some of the brittle nature of ceramics and allows them to be used for things such as flexible superconducting wire, microelectronic devices, prosthetic devices and artificial bones.
![Page 96: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/96.jpg)
Semiconductors
Elemental silicon has the same structure as diamond. The structure is different in that the energy gap between filled and empty MO’s is not as large and electrons can delocalize and make silicon a semi-conductor. At higher temperatures, more electrons get excited in the conduction bands and the conductivity of silicon increases.
![Page 97: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/97.jpg)
N-type Semiconductor
When small fraction of silicon atoms are replaced by arsenic atoms (one more valence electron), extra electrons become available for conduction and produce an n-type semi-conductor. These can conduct an electric current.
![Page 98: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/98.jpg)
P-type Semiconductor
When small fraction of silicon atoms are replaced by boron atoms (one less valence electron), an electron ‘vacancy’ is made. As electrons move, the fill the ‘hole’ and make a new one. This movement of electrons can therefore carry a current. This type of conductor (less electrons) is called a p-type semiconductor.
![Page 99: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/99.jpg)
Energy Level Diagrams for N-type and P-type Semiconductors.
![Page 100: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/100.jpg)
P-N Junction
Most important applications of semiconductors involve connection of a p-type and an n-type to form a p-n junction.
The red dots represent excess electrons in the n-type semiconductor and the white circles represent holes (electron vacancies.
![Page 101: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/101.jpg)
P-N Junction
At the junction a small number of electrons migrate from the n-type region into the p-type region. The effect of these migrations is to place a negative charge on the p-type region and a positive charge on the n-type region.
![Page 102: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/102.jpg)
P-N Junction
This charge buildup, called the contact potential or junction potential, prevents further migration of electrons. This transfer of electrons is therefore a ‘one-way’ transfer and under an external battery source will allow flow of electrons from the n to the p type regions.
![Page 103: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/103.jpg)
P-N Junction
When current is opposed it is said to be under reverse bias. When current flows easily, the junction is said to be under forward bias.
A p-n junction is a good rectifier, a device that produces a pulsating direct current from an alternating current.
![Page 104: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/104.jpg)
P-N Junction
When placed in a circuit where the current is constantly reversing, a p-n junction only transmits current under forward bias. Radios, computers and other electronic devices all use this rectifiers. This p-n junction revolutionized electronics.
![Page 105: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/105.jpg)
Molecular Solids10.6
![Page 106: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/106.jpg)
Molecular Solids
Sometimes Molecular solids can have large discrete molecular units in a lattice-type position. These molecules have strong bonds within the molecules but relatively weak between the molecules.
Common examples: Ice, dry ice (solid carbon dioxide), Sulfur (S8), Phosphorus (P4)
![Page 107: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/107.jpg)
Molecular
![Page 108: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/108.jpg)
Molecular Solids
When molecules do have dipole moments, their intermolecular forces are significantly greater, especially when hydrogen bonding is possible.
Water not only has polar bonds, a dipole moment, has hydrogen bonds, but it also can have a total of four hydrogens associated with every oxygen atom.
![Page 109: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/109.jpg)
Ionic Solids10.7
![Page 110: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/110.jpg)
Ionic Solids
Ionic solids are stable, high melting substances held together by the strong electrostatic forces that exist between oppositely charged ions.
![Page 111: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/111.jpg)
Ionic SolidsMost binary ionic solids can be
explained by the closest packing of spheres. Typically the larger ions, usually anions, are packed in one of the closest packed arrangements (hcp and ccp).
The smaller cations fit into the holes among the closest packed anions. This packing maximizes the electrostatic attractions among oppositely charged ions and minimizes the repulsion of like charges.
![Page 112: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/112.jpg)
Ionic SolidsThere are three
types of holes in closest packed structures:
1.Trigonal holes are formed by three spheres in the same layer
![Page 113: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/113.jpg)
Ionic SolidsThere are three
types of holes in closest packed structures:
2.Tetrahedral holes are formed when a sphere sits in the dimple of three spheres in an adjacent layer.
![Page 114: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/114.jpg)
Ionic SolidsThere are three
types of holes in closest packed structures:
3.Octahedral holes are formed between two sets of three spheres in adjoining layers of the closest packed structures.
![Page 115: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/115.jpg)
Ionic Solids
The holes increase in size in the order:
trigonal < tetrahedral < octahedral
The trigonal holes are so small that they are never occupied in binary ionic compounds. Tetrahedral and octahedral holes are occupied if the relative sizes of the ions allow.
![Page 116: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/116.jpg)
Ionic SolidsExample: Zinc Sulfide (ZnS) creates a ccp
structure. The Zn2+ has a radius of 70pm and the S2- ion has an ionic radius of 180pm. There are 4 spheres (atoms/anions) in a face-centered cubic unit cell and 8 tetrahedral holes. So only half of the holes in the ccp unit are filled with cations.
![Page 117: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/117.jpg)
Ionic SolidsExample: Sodium chloride can be described in
terms of a ccp structure. Na+ resides in octahedral holes. The locations of the octahedral holes in the face-centered cubic unit is marked by X. The number of spheres (anions) in the structure is the same number of octahedral holes. Since NaCl is a 1:1 binary compound. All octahedral holes are used.
![Page 118: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/118.jpg)
Example Problem
Determine the net number of Na+ and Cl- ions in the sodium chloride unit cell.
4 Na+ and 4 Cl-
![Page 119: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/119.jpg)
Example ProblemClassify each of the following substances
according to the type of solid it forms:
gold
carbon dioxide
lithium fluoride
krypton
metallic
molecular
ionic
8a
![Page 120: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/120.jpg)
Types and Properties of Solids
![Page 121: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/121.jpg)
Vapor Pressure and Changes of
State10.8
![Page 122: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/122.jpg)
Vaporization
Vaporization, or evaporation, is the process of liquid molecules escaping the liquid’s surface and forming a gas.
Vaporization is endothermic because energy is required to overcome the relatively strong intermolecular forces in the liquid. Water has strong intermolecular forces
and this increases the energy required to vaporize. Also making it a great coolant.
![Page 123: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/123.jpg)
Vaporization
The energy required to vaporize 1 mole of liquid at 1 atm is called the heat of vaporization or the enthalpy of vaporization.The symbol for this is ΔHvap.
![Page 124: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/124.jpg)
Vapor Pressure
Condensation is the process by which vapor molecules re-form a liquid.
The evaporation process occurs at a constant rate at a given temperature, and once an equilibrium has been reached, the rate of condensation will equal the rate of evaporation.
![Page 125: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/125.jpg)
Vapor PressureMolecules in a
given system are constantly escaping from and entering the liquid at high rate. However, there is not net change because the two opposite processes just balance each other.
![Page 126: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/126.jpg)
Rates of Condensation and Evaporation.
![Page 127: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/127.jpg)
Vapor Pressure
The pressure of the vapor present at equilibrium is called the equilibrium vapor pressure, or more commonly, the vapor pressure of the liquid.
A simple barometer can measure the vapor pressure of a liquid.
![Page 128: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/128.jpg)
Vapor PressureLiquid is injected at the bottom of the tube of
mercury and floats to the surface. A portion of the liquid evaporates at the top of the column, producing a vapor whose pressure pushes some mercury out of the tube.
![Page 129: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/129.jpg)
Vapor PressureWhen the system reaches equilibrium,
the vapor pressure can be determined from the change in the height of the mercury column
![Page 130: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/130.jpg)
Vapor PressurePatmosphere = Pvapor + PHg column
Pvapor = Patmosphere - Phg column
![Page 131: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/131.jpg)
Vapor Pressure
The vapor pressure of liquids vary widely. Liquids with high vapor pressures are said to be volatile. They evaporate rapidly in an open dish.
![Page 132: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/132.jpg)
Vapor Pressure
The vapor pressure of a liquid is principally determined by the size of the intermolecular forces in the liquid.Liquids with strong molecular forces
have relatively low vapor pressures because it takes so much energy for the molecules to escape.
In general, substances with large molar masses have relatively low vapor pressures due of large dispersion forces.
![Page 133: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/133.jpg)
Vapor Pressure
Vapor pressure increases significantly with temperature. In order to break intermolecular forces,
a sufficient amount of kinetic energy is needed.
As temperature of the liquid increases, so does kinetic energy of the liquid.
![Page 134: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/134.jpg)
Vapor Pressure of Water
![Page 135: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/135.jpg)
Vapor PressureThe nature of the temperature, vapor
pressure relationship is quadratic. Pvap vs. 1/T (Kelvin) gives a direct relationship.
![Page 136: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/136.jpg)
Vapor Pressure
Vapor pressure equation:
R is the universal gas constant (8.3145 J/K). In means natural logarithm.
![Page 137: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/137.jpg)
Example Problem
Using the graph, determine whether water or diethyl ether has the larger enthalpy of vaporization.
Ether has the smaller slope therefore smaller ΔHvap
![Page 138: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/138.jpg)
Example Problem
The vapor pressure of water at 25°C is 23.8 torr, and the heat of vaporization of water at 25°C is 43.9 kj/mol. Calculate the vapor pressure of water at 50°C.
93.7 torr
![Page 139: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/139.jpg)
Sublimation
Like liquids, solids have vapor pressures. When a solid sublimes, it goes directly from the solid to the gaseous state without passing through the liquid state.
Example: Dry Ice.
![Page 140: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/140.jpg)
Changes of State
Typically when a solid is heated, it will form a liquid and then boil to form a vapor. This process can be represented by a heating curve.
Temperature vs. time when energy is added a constant rate.
![Page 141: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/141.jpg)
Heating Curve
![Page 142: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/142.jpg)
Heating Curve
The plateaus in the heating curve represent the positions of phase change.
At the melting point, the temperature remains constant until the solid has completely changed to liquid.
At the boiling point the temperature remains constant as the added energy is used to vaporize the liquid
![Page 143: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/143.jpg)
Heating CurveThe energy change that occurs at the
melting point when a solid melts is called heat of fusion or enthalpy of fusion.Note that changes of state are physical
changes, although intermolecular forces have been broken, no chemical bonds have been broken.
![Page 144: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/144.jpg)
Enthalpy of Fusions and Melting Points
![Page 145: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/145.jpg)
Melting and Boiling
The melting and boiling points for a substance are determined by the vapor pressure of the solid and liquid states.
![Page 146: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/146.jpg)
Melting and Boiling
At 0°C the vapor pressure of ice is less than that of liquid. Vapor pressure of ice increases more rapidly than water.
![Page 147: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/147.jpg)
Melting and Boiling
A point is reached when the liquid and solids have identical vapor pressures. This is the melting point.
![Page 148: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/148.jpg)
Freezing Point
At a temperature at which the vapor pressure of the solid is greater than that of the liquid, the solid would sublime and the vapor would be added to the water.
![Page 149: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/149.jpg)
Freezing Point
At a temperature at which the vapor pressure of the solid is less than that of the liquid, the liquid would evaporate and the vapor would be added to the ice.
![Page 150: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/150.jpg)
Freezing Point
At a temperature at which the vapor pressures of the solid and liquid are identical, the vapor is in equilibrium. This is the freezing point of water.
![Page 151: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/151.jpg)
Melting Point and Boiling Point
The normal melting point of a liquid is the temperature at which the solid and liquid states have the same vapor pressure under conditions where the total pressure is 1 atmosphere.
The normal boiling point of a liquid is the temperature at which the vapor pressure of the liquid is exactly 1 atmosphere.
![Page 152: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/152.jpg)
Supercooled and Superheated
Changes of state do not always occur exactly at the boiling point or melting point.
Water can be supercooled below 0°C at 1 atm and remain in the liquid state. At some point the correct ordering of molecules occurs and ice forms, releasing energy in the exothermic process and bringing the temperature back up to the melting point.
![Page 153: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/153.jpg)
Supercooled and Superheated
![Page 154: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/154.jpg)
Supercooled and Superheated
Changes of state do not always occur exactly at the boiling point or melting point.
A liquid can also be superheated, or raised to temperatures above its boiling point, especially if it is heated rapidly. Boiling requires high-energy molecules to gather in the same vicinity for bubble formation. This may not happen at the boiling point.
![Page 155: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/155.jpg)
Supercooled and Superheated
Once a bubble does form, when a liquid is superheated, its internal pressure is greater than the atmospheric pressure. This bubble can burst before rising to the surface, blowing the surrounding liquid out of the container. This is called bumping and is a common experimental problem.
![Page 156: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/156.jpg)
Supercooled and Superheated
Boiling chips are often added to prevent bumping. These are bits of porous ceramic material containing trapped air that escapes on heating, forming tiny bubbles that act as ‘starters’ for the vapor bubble formation. This allows for smooth onset of boiling.
![Page 157: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/157.jpg)
Phase Diagrams10.9
![Page 158: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/158.jpg)
Phase Diagram
A phase diagram is a convenient way of representing the phases of a substance as a function of temperature and pressure. It shows which state exists at a given temperature and pressure.
Conditions for these phase diagrams are assumed to be a closed system and is plotted as temperature vs pressure.
![Page 159: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/159.jpg)
Phase Diagram
![Page 160: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/160.jpg)
Phase Diagram
The solid/liquid boundary has a negative slope. Melting point of ice decreases as
external pressure increases. This is different for most substances
other than water because the density of ice is less than that of liquid water at the melting point.
![Page 161: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/161.jpg)
Boiling Points of Water vs. Pressure
![Page 162: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/162.jpg)
Example 1
Pressure is 1 atm. Water moves through the changes of state according to the vapor pressure at the corresponding temperatures.
![Page 163: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/163.jpg)
Example 2
Pressure is 2 torr. Water will sublime at -10°C. This is when the vapor pressure of the ice is equal to the external pressure of 2 torr. Vapor pressure of liquid water is always greater than 2 torr and therefore will not form.
![Page 164: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/164.jpg)
Example 3Pressure is 4.58 torr.
When temperature reaches .01°C (273.16K), water reaches the triple point. Solid and liquid water have identical vapor pressures and all three states of water exist. This is the only condition in a closed system that allows this.
![Page 165: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/165.jpg)
Example 4
Pressure is 225 atm. Liquid water can be present at this temperature because of the high external pressure. As temperature increases, liquid gradually turns to vapor, but goes through a ‘fluid’ region.
![Page 166: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/166.jpg)
Example 4
The fluid region is neither true liquid or vapor. This unusual behavior occurs because the conditions are beyond the critical point for water.
![Page 167: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/167.jpg)
Critical PointThe critical temperature can be
defined as the temperature above which the vapor cannot be liquefied no matter what pressure is applied.
The critical pressure is the pressure required to produce liquefaction at the critical temperature
Together, the critical temperature and critical pressure define at the critical point.
![Page 168: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/168.jpg)
Critical PointThe critical point for water is 374°C
and 218 atm. Anything beyond this point, involves the intermediate “fluid” region.
![Page 169: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/169.jpg)
Phase Diagrams
The phase diagram for CO2 shows the liquid state does not exist at a pressure of 1 atm. The solid/liquid line has a positive slope, since the density of solid CO2 is greater than that of liquid CO2
![Page 170: Liquids and Solids AP Chem Unit 10. Sections Intermolecular Forces Liquid state Solid Structures Metal Structures Carbon and Silicon Networks](https://reader036.vdocuments.us/reader036/viewer/2022081415/56649db05503460f94a9eec0/html5/thumbnails/170.jpg)
THE END!!