1. Consider CsCl, which has a primitive cubic lattice with one ion occupying the corners of the cube and the other ion located in the center of the cube. The lattice parameter is a = 412.3 pm, the Madelung constant is 1.763, and the compressibility is 5.55×10–11 m2/N.
a. Estimate the lattice energy using the Born-Landé equation.
b. Estimate the lattice energy using the Born-Mayer equation using d* = 34.5 pm.
c. Estimate the lattice energy using the Kapustinskii equation.
d. Estimate the lattice energy using a Born-Haber cycle.
e. Compare the different determinations of the lattice energy. Which is most reliable? Why?
f. Do the ionic radii given in the table below accurately account for the lattice parameter? Why or why not?
g. Is this a closest packed structure? Why or why not?
2. For the following complexes, give the point group, indicate the LFSE (in units of Dq and P), and determine the number of unpaired spins.
a. [Cr(NH3)6]3+
b. [Fe(H2O)4en]3+
c. [Fe(CN)4en]–
d. fac-[CoF3Cl3]4– (fac indicates that three ligands occupy the face of the octahedron)
e. fac-[Co(NH3)3(CN)3]–