chapter9-p3_After lecture nsssssotes.pdf

HKUST chem 1012

1. CHEM 1012:
General Chemistry B
Chapter 9: Liquids and Solids
Professor Haipeng Lu (呂海鵬)
Departmentof Chemistry
The Hong Kong University of Science and Technology
Spring 2025
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Chapter #9 in the Textbook

2. Reviewquestions:
exercise1:Give the formula of compounds with the unit cell shown below
A) Re
4O
12
B) Re
3O
12
C) ReO
3
D) ReO
4
O
Re
Rhenium
Oxygen
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4. Reviewquestions:
exercise1:Give the formula of compounds with the unit cell shown below
A) Re
4O
12
B) Re
3O
12
C) ReO
3
D) ReO
4
O
Re
#Re = 4x1/4 =1
#O = 8x1/8 + 4x1/2 =3
=> ReO
3
Rhenium trioxide
Rhenium Oxygen

5. CHEM 1012: Chapter 9
CHAPTER OUTLINE
1.Intermolecular Forces
2.Some Properties of Liquid States
3.Change of States and Phase Diagrams
4.An Introduction to Structures and Types of Solids
5.Structure and Bonding in Metals and Alloys
6.Covalent Network Solids
7.Ionic Solids
8.Molecular Solids
9.Non-Crystalline Solids
Reference and Suggested Reading:
“Chemistry, an atoms first approach”, Zumdahl& Zumdahl: Chapter 9

6. inspiration
How toarrangeorangesintheclosestpacking?
52% 68% 74%

7. Structures and Types of Solids
•Amorphous Solids:
Disorder in the structures
Based on the structures, solids can be classified as
Crystalline
•Crystalline Solids:
ordered structures
•glass
•polymers
•gels
•thin films
•nanostructured
materials
Amorphous
repeat

8. Structures and Types of Solids
There are threetypes of crystalline solids.
–Atomic solids
•metals,
•non-metals (network
covalent, e.g. diamond),
•Group 8A elements (noble
gases e.g. helium, He; neon,
Ne; argon, Ar)
–Ionic solids (e.g. NaCl)
–Molecular solid (e.g. solid
carbon dioxide,ice,tablesugar)
repeat

9. Crystalline Solids
Fraction of Space Occupied by Spheres
Name Coord. no.Sphere touchingCell size% Space used
Simple cubic6 Cell edge I = 2r 52%
Body-centered8 Body diagonal 4r = (3)
1/2
l68%
Face-centered12 Face diagonal 4r = (2)
1/2
l74%
l r
repeat
Coord. no. = 12
Face-centered cubic

10. Structure and Bonding in Metals and Alloys
•Assumes that metal atoms areuniform, hard spheres.
•Spheres are packed in layers.
•Either close or non-close packing ofspheres are possible.

11. Structure and Bonding in Metals and Alloys
A single layerof spheres is closest-packed with a HEXAGONAL
coordination of each sphere
•Closest packing (common arrangements)
Assuming that metal atoms are hard,
uniform spheres:
•These spheres are packed in layers
•Each successive layer is formed when spheres
occupy a dimple formed by the spheres of the
previous layer
The Closest Packing Model
1 2
3
45
6
dimple

12. Close packed structure in 2D
What is the packing efficiency?
A
B
A
Square
Hexagonal
2∗??????∗??????
2
??????
2=
2∗??????∗??????
2
(4??????/(2)
2= 0.785
2??????=4??????
4r
a
1∗??????∗??????
2
??????∗(3/2??????)
=
1∗??????∗??????
2
(2??????)∗(3/2(2??????))
= 0.91Foryourinformationonly…

13. Close packed structure in 3D
Two Common Types of Closest Packing
•A second layerof
spheres is placed in the
indentations left by the
first layer.
•When a third layerof
spheres is placed in
the indentations of the
second layer there are
TWO choices.
•Twoformsof closest packing:
aba packing
abcpacking
identation/dimple

14. Close packed structure in 3D
Two Common Types of Closest Packing
•A second layerof
spheres is placed in the
indentations left by the
first layer.
•When a third layerof
spheres is placed in
the indentations of the
second layer there are
TWO choices.
•Twoformsof closest packing:
aba packing
abcpacking
identation/dimple

15. Close packed structure in 3D: ABC vs ABA
Two Common Types of Closest Packing
aba packing
ABABABAB…
abcpacking
ABCABCABC…

16. Close packed structure in 3D: ccp
abcpacking: Cubic Closest Packing (Face-Centered Cubic)
abbreviation:ccpor fcc
Pattern: ABCABCABC….
•The spheres in the 3
rd
layer occupy dimples in the 2
nd
layer
•Spheres in the 3
rd
layer do not rest above spheres in
the 1
st
layer
•The 4
th
layer is like the 1
st
•The resultant structure is termed a cubic closest packed
(ccp) structure
•The spheres in every fourth layer occupy the same
vertical position
•In abc packing, the unit cell is face-centered cubic

17. Close packed structure in 3D: ccp
abcpacking: Cubic Closest Packing (Face-Centered Cubic)
abbreviation:ccpor fcc
Contains a cuboctahedron
A
B
C

18. Close packed structure in 3D: ccp
Atoms are at corners
and face-centers
abcpacking: Cubic Closest Packing (Face-Centered Cubic)
abbreviation:ccpor fcc
Face-Centered Cubic
Number of balls in a unit cell:
8x1/8 + 6x1/2 =4

19. Close packed structure in 3D: hcp
aba packing: Hexagonal Closest Packing
abbreviation:hcp
•The 2
nd
layer is like the 1
st
, but it is displaced, so that each
sphere in the 2
nd
layer occupies a dimple in the 1
st
layer
•The spheres in the 3
rd
layer occupy dimples in the 2
nd
layer
•Spheres in the 3
rd
layer lie directly over those in the 1
st
layer
•The resultant structures are called hexagonal closest packed
(hcp) structures
•The spheres in every other layer occupy the same vertical
position
•When the spheres are aba closest packed,
the unit cell is a hexagonal prism
Pattern: ABABABAB….

20. Close packed structure in 3D: hcp
aba packing: Hexagonal Closest Packing
abbreviation:hcp

21. Close packed structure in 3D: hcp
Difficulttocalculate
thecontribution
fromtheblue
spheres
The unit cell is a hexagonal prism
1/3
???
120°
No!!!
aba packing: Hexagonal Closest Packing
abbreviation:hcp

22. Close packed structure in 3D: hcp
Contains an anti-cuboctahedron
The unit cell is a
hexagonal prism
Number of balls in a unit cell =
3 + 2x1/2 +12x1/6 = 6
Red,insideBlue,faceBlue,cornerofhexagonal prism
aba packing: Hexagonal Closest Packing
abbreviation:hcp

23. ccpvs hcp
Common Characteristics of the hcpand the ccpStructures
•Each sphere in both structures possesses 12equivalent nearest
neighbors
anti-cuboctahedron
cuboctahedron

24. Structure and Bonding in Metals and Alloys
Examples of Crystal Structures of Metals:
close-packed structures (for reference only)
Examples of fcc/ccpmetalsinclude
nickel, silver, gold, copper, and aluminum.
Examples of hcpmetalsincludezinc,
titanium, zirconium, magnesium.

25. Structure and Bonding in Metals and Alloys
Examples of Crystal Structures of Metals:
non-close-packed structures (for reference only)
Rhombohedral
Na

26. Structure and Bonding in Metals and Alloys
Table: The most stable crystal structures assumed by the elements in their solid phase
He
hcp
Li Be B C N O F Ne
bcc hcp rhd hcp sc-ccp
Na Mg Al Si P S Cl Are
bcc hcp ccpd scor tetccp
K Ca Sc TiV Cr Mn Fe CoNi CuZn Ga Ge As Se Br Kr
bcc ccphcp hcp bcc bcc bcc bcc hcpccpccphcp scd rhhcp or ccp
RbSrY ZrNbMo TcRuRhPdAgCdIn SnSbTeI Xe
bcc ccphcphcpbcc bcc hcphcpccpccpccphcptettetrh hcporccp
Cs BaLa HfTa W Re OsIrPt Au Hg Tl PbBi Po At Rn
bcc bcc hcp hcp bcc bcc hcp hcp ccpccpccprhhcp ccprhmono -ccp
Note:sc= simple cubic, tet= tetragonal, rh= rhombohedral, d = diamond
or = orthorhombic, mono = monoclinic
The Crystal Structures of Metals(for reference only)
Most of them tend to be closest packed…

27. Structure and Bonding in Metals and Alloys
Bonding Model in Metals
•A successful bonding model for metals must consider:
•Malleability, Ductility, Efficient uniform conduction of heat and electricity
•Bonding models for metals include:
•Electron sea model
•Band model (MO model)[Out of scope of this course]
metal is hammered or drawn into a wire…

28. Structure and Bonding in Metals and Alloys
Bonding Model in Metals
Outermostelectronswanderfreelythrough
metal. Metal consistsof cationsheldtogether
bynegatively-chargedelectron"glue.“
Na
3s
1
Mg
3s
2
•Electron sea model
•A regular array of metal cations are considered
to be in a sea of mobile valence electrons
•Mobile electrons conduct heat and electricity
•Ions can freely move around when the metal is
hammered or drawn into a wire

29. Structure and Bonding in Metals and Alloys
Metallic Bonding and Properties
A.Outermostelectronswanderfreelythrough
metal.
B.Why metalsaregoodconductorsof
electricity?
Freeelectronscan moverapidlyin
responsetoelectricfields.
C.Whymetalsaregoodconductorsof heat?
Freeelectronscan transmitkineticenergyrapidly.
D.Whymetalsaretough, butare areductile?
Thelayersof atomsin metal arehard topullapart becauseof theelectronsholding them
together.But individualatomsarenot heldtoanyotherspecificatoms, henceatomsslip easily
pastoneanother.

30. Structure and Bonding in Metals and Alloys
Structures of Alloys –a Blend of Metallic Elements
Maybe formed, if
-radii of the elements are similar.
-structure of pure componentmetals are the same.
-electropositive character are similar.
(a)Substitutionalsolidsolutions:
Replacement of one type of
metal atoms in a structure by
another.
(b)Interstitialsolidsolutions of non-metals:
Additional smallatoms (e.g. C, B, N) occupy
holes within the lattice of original metal
structure

31. Structure and Bonding in Metals and Alloys
Examples of Alloys
Steel is an InterstitialAlloy
Brass is a substitutionalalloy
Zn

32. Structures and Types of Solids
There are threetypes of crystalline solids.
–Atomic solids
•metals,
•non-metals (network
covalent, e.g. diamond),
•Group 8A elements (noble
gases e.g. helium, He; neon,
Ne; argon, Ar)
–Ionic solids (e.g. NaCl)
–Molecular solid (e.g. solid
carbon dioxide,ice,tablesugar)
repeat

33. Covalent Network Solids
•A crystalline covalentnetwork solid is a solid in which atoms are
covalently bonded to each other.
•These molecules areheld together bycovalent bonds.
•They are generally hardandhavehigh meltingtemperature.
•They are generally ineffective conductors of heat and electricity
Network Solids -An Introduction
•Network solids are those atomic solids that contain directional
covalent bonds which form solids that can be viewed as “giant
molecules”

34. Covalent Network Solids
Diamond has the highest hardness of any bulk material.
The propertiesoriginate from the ___________________.
Example 1. Diamond
strong covalent bonding
•Hardest naturally occurring substance
•Each C atom is surrounded by a tetrahedral
arrangement of other C atoms
•Structure as per the localized electron model:
•Stable structure is obtained via covalent bonds
•Formed by the overlap of sp
3
hybridized C
atomic orbitals

35. Covalent Network Solids
Example 2. Graphite
•Slippery, black, and a conductor of heat and electricity
•Structure is based on layers of C atoms arranged in fused six-membered rings
•Structure as per the localized electron model:
•Shows trigonal planar arrangement
•120-degree bond angles
•sp
2
hybridization
•Three sp
2
orbitals on each C atom fuse to form σbonds with three other
C atoms
•One 2porbital remains unhybridized, perpendicular to the plane

36. Covalent Network Solids
•Graphite is another example of a network solid. In each layer, atoms are bonded by covalent bonds.
Layers are held together with van der Waals forces.
•Graphite is an electrical conductor due to the
•Graphite hasdry lubricating properties,due to
vast electron delocalization within the carbon layers
relatively weak van der Waals forcesbetween sheets
Example 2. Graphite
•Used as lubricants in locks
•Slipperiness can be attributed to the strong bonding within the
C atom layers rather than between the layers (vanderWaals).
•By applying 150,000 atmpressure at 2800°C, graphite can be
converted to a diamond

37. Covalent Network Solids
Quartzis the second-most-abundant mineralin the
Earth‘s continental crust. It is made up of a continuous
framework of onesilicon–fouroxygen tetrahedra, with
each oxygen being shared between two tetrahedra.
Owing to its high thermal and chemical stabilityand
abundance, quartz is widely used many large-scale
applications related to abrasives, foundry materials,
ceramics, and cements. SiO
Si
O
O
O
O
Example 3. Quartz (SiO
2)
onesilicon–fouroxygen
oneoxygen–twosilicon
Quartz holds the empirical formula:SiO
2

38. Covalent Network Solids
Silicon is a solid at room temperature, with
relatively high melting and boiling points
of approximately 1,400
o
Cand 2,800
o
C,
respectively.
Example 4. Silicon
tetrahedral arrangement of Si atoms

39. Structures and Types of Solids
There are threetypes of crystalline solids.
–Atomic solids
•metals,
•non-metals (network
covalent, e.g. diamond),
•Group 8A elements (noble
gases e.g. helium, He; neon,
Ne; argon, Ar)
–Ionic solids (e.g. NaCl)
–Molecular solid (e.g. solid
carbon dioxide,ice,tablesugar)
repeat

40. Ionic Solids
•A crystalline ionic solidis composed of cations and anions
(e.g. NaCl).
•The solids are held together by ionic bonding.
•Ionic solids are very hard and brittle withhigh melting points.
Why?
Strong ionic bond, deformation will break the bonds.
•The structures can be regarded as derived from arrays in which
the anions (sometimes the cations) stack together in fccor hcp
(or others) patterns and the counter ions occupy the holes.

41. Ionic Solids
Holes from Packing of Spheres
There are three types of holes in Closest Packed Structures
1)Trigonal holes are formed by three spheres in the same layer.
•Very small and are never occupied in binary ionic compounds

42. Ionic Solids
2)Tetrahedral holes are formed when a
sphere sits in the dimple of three
spheres in an adjacent layer.
Holes from Packing of Spheres
fourspheres in two adjacent layers

43. Ionic Solids
The Tetrahedral Hole in the Face-Centered Cubic Unit Cell
(a)The location (red X) of a tetrahedral hole in the face-centeredcubic unit cell
(b)One of the tetrahedral holes
(c)The unit cell for ZnS where the S
2–
ions (yellow) are closest packed with the Zn
2+
ions
(purple) in alternating tetrahedral holes
HowmanyoftheTetrahedral Hole in the Face-Centered Cubic Unit Cell?8 tetrahedral holes

44. Ionic Solids
Holes from Packing of Spheres
•Formed by six spheres in two adjacent
layers
•The number of octahedral holes in a
ccpstructureis the same as the
number of packed anions
3)Octahedral holes are formed between two sets of three spheres
in adjoining layers of the closest packed structures.
x x x
six spheres in two adjacent layers
4 = 1+12*1/4

45. Ionic Solids
Holes from Packing of Spheres
4) Cubicholes are present in simple cubic packing
For spheres of a given diameter, the holes increase in size in the order:
trigonal < tetrahedral < octahedral< cubic
Large ions tend to be in the holes of large size.
A math problem: can you calculate the size of trigonal, tetrahedral, octahedral, and cubic holes, respectively??

46. Ionic Solids
Examples of ionic solid
NaCl
CsCl
ZnS
CaF
2
Cl-: SC packing
Cs
+
: Cubicholes
Cl-: fccpacking
Na
+
: Octahedral
holes
S
2-
: fccpacking
Zn
2+
: Tetrahedral
holes
Ca
2+
: fccpacking
F
-
: Tetrahedral
holes

47. Ionic Solids
exercise1:Describe the structure of Rock salt (NaCl)
structure:
Whatistheclosepackingtypeofanion?
Whatisthetype of holes occupied by cation?
A:Face Centered Close Packing,Tetrahedral holes
B:Face Centered Close Packing,Octahedral holes
C:Hexagonal Close Packing,Tetrahedral holes
D:Hexagonal Close Packing,Octahedral holes
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49. Ionic Solids
exercise1:Describe the structure of Rock salt (NaCl)
structure:
Whatistheclosepackingtypeofanion?
Whatisthetype of holes occupied by cation?
A:Face Centered Close Packing,Tetrahedral holes
B:Face Centered Close Packing,Octahedral holes
C:Hexagonal Close Packing,Tetrahedral holes
D:Hexagonal Close Packing,Octahedral holes
abcpacking: Cubic Close Packing (also
called Face Centered Close Packing)
abbreviation:ccpor fcc
x x x
Na
+
Cl
-

50. Ionic Solids
exercise2:Describe the structure of Zinc blends (ZnS):
What is the close packing type of anion?
What is the type of holes occupied by cation?
A:Face Centered Close Packing,Tetrahedral holes
B:Face Centered Close Packing,Octahedral holes
C:Hexagonal Close Packing,Tetrahedral holes
D:Hexagonal Close Packing,Octahedral holes
Interactive ZOOM meeting for submittinganswers
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52. Ionic Solids
exercise2:Describe the structure of Zinc blends (ZnS):
What is the close packing type of anion?
What is the type of holes occupied by cation?
A:Face Centered Close Packing,Tetrahedral holes
B:Face Centered Close Packing,Octahedral holes
C:Hexagonal Close Packing,Tetrahedral holes
D:Hexagonal Close Packing,Octahedral holes
X
X

53. Structures and Types of Solids
There are threetypes of crystalline solids.
–Atomic solids
•metals,
•non-metals (network
covalent, e.g. diamond),
•Group 8A elements (noble
gases e.g. helium, He; neon,
Ne; argon, Ar)
–Ionic solids (e.g. NaCl)
–Molecular solid (e.g. solid
carbon dioxide,ice,tablesugar)
repeat

54. Molecular Solids
•A crystalline solid with moleculesheld together by intermolecular forces.
•These compounds are fragile (compared to ioniccompounds) with melting
points dependent on theintermolecular forces holding them together.
•They do not conduct electricity
Example 1, dry Ice
•At 1 atm,
sublimation occurs
at −78.5
o
C.
•CO
2molecules are
held by London
dispersion forces.

55. Molecular Solids
Example 2,
Ice
m. p. = 0
o
C
H
2O molecules are held by hydrogen bonding.
(Common ice crystals are
symmetrical and have a
hexagonal pattern.)

56. A Summary of Crystalline Solids
A Summary of Types, Bondingand Properties ofCrystallineSolids

57. Structures and Types of Solids
•Amorphous Solids:
Disorder in the structures
Based on the structures, solids can be classified as
Crystalline
•Crystalline Solids:
ordered structures
•glass
•polymers
•gels
•thin films
•nanostructured
materials
Amorphous
repeat

58. Non-Crystalline Solids
There are many non-crystalline solids (for information)
Example 1,
Glass
Glass is an amorphous(non-crystalline) solid material.
Glasses are typically brittle and optically transparent.
The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime
glass, composed of about 75% silica (SiO
2) plus Na
2O, CaO, and several minor additives.

59. Non-Crystalline Solids
Example 2
Ceramic
Typically made from clays (which contain silicates [SiO.
4−x]
n) and hardened by firing at high
temperatures.
A ceramic is heterogeneous: Minute crystals of silicates [SiO.
4−x]
nare suspended in a glassy cement.
It is a mixture of silicates with formula such as K
2O.Al
2O
3.6SiO
2or Na
2O.Al
2O
3.6SiO
2.
Ceramicsare strong, brittle, and resistant to heat and attack by chemicals.
There are many non-crystalline solids (for information)

60. inspiration
How toarrangeorangesintheclosestpacking?
abcpacking: Cubic Close Packing (also
called Face Centered Close Packing)
abbreviation:ccpor fcc
aba packing: Hexagonal Close Packing
abbreviation:hcp
hcp ccpor fcc

61. SummaryofChapter 9(part 3)
Liquids and Solids
1.Intermolecular Forces
2.Some Properties of Liquid States
3.Change of States and Phase Diagrams
4.An Introduction to Structures and Types of Solids
5.Structure and Bonding in Metals and Alloys
6.Covalent Network Solids
7.Ionic Solids
8.Molecular Solids
9.Non-Crystalline Solids
Trigonal Tetrahedral
Closestpacking
Substitutional
Interstitial
Electronseamodel
Cubic(ccp,fcc)
Hexagonal(hcp)
alloy
networksolids
Octahedral
Holesfrompackingofspheres
metal
molecularsolids
ionicsolids

62. Suggested Reading and Homework Exercises
Reading:
Z&Z, Chapter 9, pp. 362-407.
Questions/Exercises:
Z&Z, Chapter9:
Reviewquestions:pp. 408, 1 ~ 11
Questions/exercises: p409, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33;
p410, 35, 37, 39, 41; 43, 45; 47, 49, 51, 51, 53, 55, 57, 59, 61, 63, 67, 69,
71; 73, 75, 77, 79, 81, 83, 85, 87; 89, 91, 93, 95, 97, 99, 101, 103, 105, 107.
Challenge Problems(optional): p410g, 133, 135, 137, 139, 141, 143, 145, 147.