Crystal Chemistry Quiz 3 Information

Rutile, Graphite, and Hexagonal Boron Nitride

Rutile - Chemical Formula

TiO2

Graphite - Chemical Formula

C

Hexagonal Boron Nitride - Chemical Formula

h-BN

Rutile - Coordination Number

Ti - 6, O - 3

Graphite - Coordination Number

3

BN - Coordination Number

B - 3, N - 3

Rutile - bond length

1.9 A

Graphite - bond length

1.4 A in layers

3.3 A between layers

h-BN - bond length

1.45 A in sheets

3.33 A between sheets

Rutile - Crystal System

Tetragonal

Graphite - Crystal System

hexagonal

h-BN - Crystal System

hexagonal

Rutile - lattice parameters

a = b = 4.58 A, c = 2.95 A

α = β = γ = 90°

Graphite - lattice parameters

a = b = 2.456, c = 6.696

Rutile - ideal density

3.51 g/cc

Graphite - ideal density

2.2 g/cc

Rutile - hardness

6

Graphite - hardness

2

h-BN - hardness

1.5-2

Rutile - molecules/unit cell

2 MOLECULES

Ti = 8*(1/8) + 1 = 2

O = 4*(1/2) + 2 = 4

Graphite - molecules/unit cell

4 MOLECULES

C = 8*(1/8) + 2*(1/2) + 4*(1/4) + 1 = 4

h-BN - molecules/unit cell

2 MOLECULES

B = 8(1/8) + 1 = 2

N = 2(1/2) + 4(1/4) = 2

Rutile - isomorph

SnO2 (cassiterite)

Rutile - polymorph

Anatase, Brokite

Graphite - polymorph

Diamond

Rutile - uses

1. Electrical uses in sensors and electrocatalysis

2. Pigment in powder form

3. Capacitors (k = 120)

Graphite - uses

1. Crucibles in reducing environments

2. Lubricants

3. Pencils

h-BN - uses

1. Hard abrasive material

Rutile - symmetry elements

1. 5 mirror planes

2. point group: 4/mmm

3. inversion center

Graphite - symmetry elements

1. 7 mirror planes

2. inversion center

h-BN - symmetry elements

1. 7 mirror planes

2. inversion center