HW 1 Inorganic Materials
Chemistry
Name:
Points: C7780 Date:
Max. 100 points Fall 2018 A
1. (20 pts) In the crystalline Cu2O, oxygen atoms possess coordination number 4. What is the
coordination number of Cu? Show how you arrived to the answer.
2. (10 pts) A unit cell has in general shape of a) cube b) tetrahedron c) parallelepiped
3. (20 pts) Give stoichiometric formulas for the cubic structures in the picture below. a =
Heusler compound, b = Half-Heusler compound.
4. (25 pts) An octahedral structural unit CoO6 possesses following CoO bond distances (in
Å). Use Pauling Rules to establish whether the cobalt cation is in oxidation state 2+ or 3+.
Use parameters R0 = 1.692 Å and B = 0.30.
2x Co1–O1 2.1033(12)
2x Co1–O2 2.0703(12)
2x Co1–O3 2.1204(12)
5. (25 pts) 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 I and II
(assume counter diffusion of both cations) and calculate the Kirkendall ratio for this process.
I II
CaO CaCeO3 CeO2