HW 1 Inorganic Materials
Chemistry
Name:
Points: C7780 Date:
Max. 100 points Fall 2010 A
1. Assume that CaO reacts with CeO2 and forms CaCeO3. What could be the structure type of
this compound? ______________
Write balanced chemical equations for the reactions taking place at the interfaces (assume
counter diffusion of both cations) and calculate the Kirkendall ratio for this process.
I II
2. Derive Miller indices for planes that intersects the cell axes at a/2, 2b/3, 2c.
3. Give stoichiometric formulas for these structures. Large atoms = A, small atoms = B
4. 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.
5. Maghemite γ-Fe2O3 crystallizes in a defect inverse spinel structure (as Fe3O4), but some
positions of Fe3+
in octahedral holes must be vacant, in order to maintain stoichiometry. What
part of these holes must be empty in comparison with Fe3O4.
= vacancy, empty hole, (X) = tetrahedral position, [Y] = octahedral position
Fill stoichiometric coeficients at the horizontal lines:
(Fe)___ [Fe___, ____] O4
CaO CaCeO3 CeO2