Chemistry 401

Intermediate Inorganic Chemistry

University of Rhode Island

Exam 1

October 1, 1999

1. Give the n, l, and all of the ml quantum numbers for the first allowed g orbital. Sketch the radial wave function as a function of distance from the nucleus. How many radial and angular nodes are found for this orbital?

Answer

2. Find the electron configuration and ground state term symbol for a) Co; b) Co2+; c) Cl; d) Cl; e) La; f) Cu; g) Cr.

Answer

3. A periodic property not discussed in class is the absolute hardness, η, defined as η = (IP-EA)/2. Calculate η (in units of eV) for the elements Li to F. What is the general trend across this row of elements? How does the trend in η compare to the trend in Z*?

Answer

4. In fluorite, CaF2, the calcium ions form the lattice and the fluoride ions occupy tetrahedral holes. Why is this unusual? Would you expect this to be a closest packed lattice, in the sense that the calcium ions are "touching"? Why or why not?

Answer

5. The experimental lattice energies are 912 kJ/mol for AgCl and 750 kJ/mol for NaCl. The two solids have identical structures (both are rock salt) and the cationic radii for Ag+ and Na+ are identical, 0.102 nm for octahedral holes. Explain why the lattice energies are so different despite the fact the two compounds have identical structures.

Answer