Chemistry 401

Intermediate Inorganic Chemistry

University of Rhode Island

Final Exam

December 20, 2010
open book, open notes

1. Kumar, Zhu, Walsh, and Prabhakar (pages 38 – 46) studied the use of Pd(H2O)42+ as a catalyst for peptide bond hydrolysis. Draw the structure, name, and find the point group of the complex.

Answer

2. Grant, Wang, Dixon, and Christie (pages 261 – 270) determined the heats of formation of a number of xenon fluorides, including XeF3+ and XeF3. Draw the Lewis dot structures for these two ions, estimate all of the bond angles, and give the point group of each.

Answer

3. Cotton, Chiarella, Dalal, Murillo, Wang, and Young (pages 319 – 324) used EPR spectroscopy to find the type of orbital in which the unpaired electron in Os27+ resides. Draw a molecular orbital diagram for this ion, using only d valence orbitals, and predict the orbital occupation of the unpaired spin.

Answer

4. Szajna-Fuller and Bakac (pages 781 – 785) investigated the reactions of rhodium hydrides with hydroxide ion and dioxygen. Consider a typical reaction, shown below:

LRhH+(aq) + OH(aq) → LRh(aq) + H2O(l)

L represents ligands that occupy 5 coordination sites and have a net –1 charge. Identify the oxided and reduced species. Predict the product of the reaction of LRhH+ with dioxygen.

Answer

5. Xu, Li, Xie, King, and Schaefer (pages 1046 – 1055) considered the use of BF as a ligand to substitute for CO. Fe(CO)4BF was their prototype compound. Write the Lewis dot structure for BF and predict which atom acts as the Lewis base end in the complex. Do you expect the iron complex to be stable by the EAN rule? Why or why not?

Answer

6. Derzsi, Dymkowski, and Grochala (pages 2735 – 2742) pondered the existence of a compound with stoichiometry AgSO4. They suggested three possibilities: Ag(II)SO4; Ag(I)2S2O8; and Ag(I)Ag(III)(SO4)2. Estimate the spin only magnetic moment (in units of Bohr-magnetons) for each representation of silver (II) sulfate. Could the spin moment be used to distinguish between the different possibilities? Why or why not?

Answer

7. Lundberg, Persson, Eriksson, D'Angelo, and De Panfilis (pages 4420 – 4432) analyzed the ionic radii of Pm3+. Find the electron configuration and ground state term symbol for Pm3+. They found that the ionic radii of Pm3+ were: 1.146 Å for coordination number 9, 1.090 Å for coordination number 8, 1.054 Å for coordination number 7, and 0.971 Å for coordination number 6. Explain this trend.

Answer

8. Singh and Xu (pages 6148 – 6152) studied the decomposition of hydrazine. Two possibilities are:

NH2NH2(aq) → N2(g) + H2(g)

NH2NH2(aq) → NH3(aq) + N2(g)

Balance each equation. Find the standard electrochemical potential under acidic conditions and under basic conditions. What is the preferred decomposition route under acid and base? Explain your decision for each condition.

Answer

9. Zeng, Gerken, Beckers, and Willner (pages 9694 – 9699) reported the synthesis and characterization of carbonyl diazide, CO(N3)2. Draw the Lewis structure showing nonzero formal charges and predict all of the bond angles for this compound.

Answer

10. Gao (pages 10409 – 10414) investigated the size effects of small semiconductor clusters (these are also sometimes known as quantum dots). Predict electronic structure of the “bands” in a semiconductor that is not large enough to have completely delocalized metallic-type bonds. Hint: start with atoms and build the molecular orbitals.

Answer