Bonding 3 Flashcards Preview

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Flashcards in Bonding 3 Deck (31)
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1
Q

Seven types of crystal systems

A

Cubic, tetragonal, hexagonal, rhombohedral, orthorhombic, monoclinic, triclinic

2
Q

Cubic NaCl

A

Cell edges: a = b = c

Cell angles: alpha = beta = gamma = 90 degrees

3
Q

Tetragonal Hg(CN)2

A

Cell edges: a = b x= c

Cell angles: alpha = beta = gamma = 90 degrees

4
Q

Hexagonal PbI2

A

Cell edges: a = b = c x= d
Cell angles: alpha = beta = gamma = 120 degrees
The edge d is perpendicular to the plane described by a, b, and c

5
Q

Rhombohedral NaNO3

A

Cell edges: a = b = c

Cell angles: alpha = beta = gamma x= 90 degrees

6
Q

Orthorhombic K2CrO4

A

Cell edges: a x= b x= c

Cell angles: alpha = beta = gamma = 90 degrees

7
Q

Monoclinic K3Fe(CN)6

A

Cell edges: a x= b x= c

Cell angles: alpha = gamma = 90 degrees, beta x= 90 degrees

8
Q

Triclinic CuSO4•5H2O

A

Cell edges: a x= BCM = c

Cell angles: alpha x= beta x= gamma

9
Q

Simple cubic primitive unit cell (P)

A

Contains only atoms at the corners

10
Q

Body-centered unit cell (bcc)

A

Contains atoms at the corners as well as at the center of the unit cell

11
Q

Face-centered unit cell (FCC)

A

Contains atoms at its corners and in the center of each face

12
Q

Four types of crystalline solids

A

Ionic solids
Covalent solids
Molecular solids
Metallic solids

13
Q

Ionic solids

A
Made of (+) & (-) ions arranged in regular arrays; each job is surrounded by ions of the opposite charge
Hard brittle, and have high melting and boiling points; poor conductors of electricity
14
Q

Covalent solids

A

Made of atoms held together by very strong covalent bonds; very hard and high melting points; usually poor conductors of heat and electricity

15
Q

Molecular solids (H2O, sucrose, I2, P4)

A

Made of neutral atoms; held together by dipole forces or dispersion forces; soft and poor conductors of heat and electricity

16
Q

Metallic solids

A

Are made of one closely packed metal element; free valence e- circulate soured metallic cations making them goof electricity and heat conductors; high melting points

17
Q

Close-packed structures

A

When in some substances, the atoms are packed together as closely as possible

18
Q

Tetrahedral hole (t-hole)

A

Void created four spheres (3 in the 1st and 1 above) create a regular tetrahedron

19
Q

Octahedral holes (o-holes)

A

Six spheres (3 in 1st layer and 3 in 2nd layer with layers offset by 60 degrees)

20
Q

Triangular hole

A

Between 3 adjacent spheres in the same layer

21
Q

Size of holes

A

Triangular< tetrahedral< octahedral

22
Q

Hexagonal close packing

A

When sphere of 3rd layer lie directly above spheres of 1st layer

23
Q

If there are N atoms jn a crystal

A

There are N O-holes and 2N T-holes

24
Q

Cell volumes and length cubic-close packing

A
L = 2r
V = L^3 = 8r^3
25
Q

Cell volumes body-centered cubic cell

A
L = (4/sqroot(3))r
V = ((4/sqroot(3))r)^3 = (64/3•sqroot(3))r^3
26
Q

Cell volume face centered cell

A
L = (4/sqrt(2))r
V = ((4/sqrt(2))r)^3 = (32/sqrt(2))r^3
27
Q

Coordination number (CN)

A

The number of an atom or ion’s closest neighbors within the lattice; 1-6; smaller the surrounding atom and larger the center atom usually the higher the CN

28
Q

Cohesive energy

A

The difference in energy between free ions and a solid

29
Q

Lattice energy

A

The sum of the energies of interaction of the ions in a crystal

30
Q

Madelung constant

A

Compressibility data that is used to theoretically evaluate the coulombic interactions in a lattice

31
Q

Born-Haber Cycle

A

A calculation of the total energy of a crystal determined by considering all of its formation steps and including the lattice energy contribution