HW 1 Inorganic Materials
Chemistry
Name:
Points: C7780 Date:
Max. 100 points Fall 2013 A
1. (8 pts) A unit cell has in general shape of a) cube b) tetrahedron c) parallelepiped
2. (12 pts) In the crystalline Cu2O, oxygen atoms possess coordination number 4. What is the
coordination number of Cu? Show how you arrive to the answer.
3. (30 pts) A solid state reaction between Ni and NiBi3 discs leads to the product shown
below. Consider three cases:
a) only Ni diffuses through the interfaces
b) only Bi diffuses through the interfaces
c) both Ni and Bi diffuse through the interfaces at the same rate
Calculate for each case the Kirkendall ratio, compare your results with Figure 5, and suggest
which mechanism is the most plausible.
4. (15 pts) A (111) diffraction in the powder X-ray diffractogram appears at 41 degree 2
when Cu K radiation was used ( = 1.54059Ǻ).
a) What is the value of the interplanar distance dhkl ?
b) What would be the value of the diffraction angle when Mo K radiation is used instead (
= 0.70932 Ǻ).
c) The relationship between dhkl and cubic lattice parameter a is:
2
222
2
1
a
lkh
d hkl


Calculate the cubic cell size.
5. (15 pts) Give stoichiometric formulas for these structures. Large atoms = A, small atoms =
B
6. (20 pts) Specific surface area of α-Fe2O3 was measured by nitrogen adsorption at 77 K and
its value is 120 m2
g1
. Density of this oxide is 5.277 g cm3
. Calculate the particle size
assuming a spherical particle shape.