INORGANIC CHEMISTRY 321 FINAL EXAM
May 7, 1997
Name
8 pts 1.List the three most prevalent transition metals in the human body in order of decreasing quantity.
10 pts 2.The ionic radius of K+ is 133 pm, while the ionic radius of Cu+ is 96 pm. Explain why the radius of Cu+ is smaller than that of K+.
16 pts 3.The addition of SbF5 to liquid hydrogen produces a superacid. Superacids are capable of acting as acids toward many compounds that we normally expect not to act as bases. For example, in the following reaction, HF acts as a base: SbF5 + 2 HF SbF6- + H2F+
Write Lewis structures for and predict the molecular geometries of the reactants and products.
16 pts 4.As I'm sure you recall, B(OH)3 acts as an acid, Al(OH)3 is amphoteric, and M(OH)3 are basic where M = Ga and In. Boric acid is commonly used in eyewash solutions in chemistry laboratories to neutralize bases splashed in the eye. Its' pKa is ~9. Write a reaction for the hydrolysis of boric acid showing its' conjugate base. What is the ~pKb for the conjugate base of B(OH)3? Would you expect the value of the pKa of Al(OH)3 to be greater or less than 9? Why?
20 pts 5.Given the following reactions and Latimer diagram (in an acidic solution), will any of the chromium species oxidize or reduce water, and if so, which ones? Will any of the species disproportionate?
2 H+ + 2e- H2 0.00 V
H2O 1/2 O2 + 2 H+ + 2e- -1.23 V
14 pts 6.Silver is sometimes found in nature as large nuggets; more often it is found mixed with other metals and their ores. An aqueous solution containing cyanide ion is often used to extract the silver using the following reaction that occurs in basic solution:
Ag(s) + CN-(aq) + O2(g) Ag(CN)2-(aq)
Balance this equation in a base.
21 pts 7.Describe in as much detail as possible how mined iron ores are converted into steel. Simply discuss the importance and relevant equations to 2 of the following 3: Haber, Hall, or Contact Processes.
16 pts 8.Describe how you would make the following three elements (and one compound) in the laboratory: H2, O2, CO2, and Cl2. Simple reactions will suffice.
20 pts 9.Complete and balance ten of the following reactions. Cross out the two you do not want graded.
a) aluminum metal and dilute hydrochloric acid
b) aluminum metal and aqueous sodium hydroxide
c) calcium hydride and water
d) aqueous calcium hydroxide and carbon dioxide gas
e) calcium metal and liquid ammonia (followed by evaporation of the ammonia)
f) heating a solution of ammonium nitrite
g) heating tetraphosphorusdecaoxide with carbon
h) calcium carbonate and heat
i) P4O6 and water
j) iodinemonochloride and water
k) quicklime and water
l) chlorine gas and brine (containing bromide ion)
12 pts 10.Below is an Ellingham diagram for the conversion of mercury to mercury(II) oxide. Why does the line change its slope? How would you extract mercury?
12 pts 11.Using the Latimer diagram in question #5, draw a Frost diagram (-nE° vs. Oxidation Number) for chromium in an acid solution.
12 pts 12.a) Give the systematic name for the coordination compound [Fe(en)2(OH)2]2SO4
b) Draw the coordination compound(s) amminebromodioxalotocobalt(II) chloride. Hint: Is there more than one stereoisomer and also, the oxalato ligand is C2O42- and is bidentate and can be represented by .
8 pts 13.Do the two coordination compounds in question #12 fit the eighteen electron rule?
15 pts 14.Match the following element with one of its biological features (each number is used only once):
A.Mg 1. lack of this element causes goiters
B.Pb 2.affects brain particularly in children
C.Al 3.particularly, the organometallic compound is toxic
D.Hg 4.particularly toxic to fish
E.Zn 5.this element is found in hemocyanin
F.S 6.found in chlorophyll
G.Mo 7. uses hemoglobin to be transported
H.Ca 8.a micronutrient (deficiency can cause a fatal heart condition)
I.Co 9.found in cysteine
J.Se 10.found in nitrogenase
K.Fe 11.found in Vitamin B12
L.Pt 12.used in treatment of cancer
M.O 13.found in hemoglobin
N.I 14.appears to be useful due to its structure and acidic properties
O.Cu 15.found in bones and teeth
20 bonus Fill in the following portion of the crossword puzzle:
ACROSSDOWN
47. The commercially most important halogen32. A Group 9 element that forms many inert
49. A multidentate complexd6 coordination complexes
47. Metallic element in limestone