j t1f1 - university of massachusetts...
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Name KE-'f' 1) {9 pts} For each ofthe following pairs of complexes, identify the one that has the larger lfSE and
EXPLAIN your choic~·_-.......
a. [Fe(CN)J3- 0 [Ru(CN)6]3
ca fOU PLFSf- 1r1c.le~SC- tx.5 ~ou do\.\.JY1 ~
b.
c.
(5 S fronj P, leI
2) {S pts} [Cu(phenhr is an intensely orange colored compound. What kind of electronic transition (d-d,
LMCT, MlCf, fluorescence, phosphorescence, etc.) gives rise to this color? K[MnO,d is a deep purple
color (as those of you have used it to oxidize organic molecules will recall). What kind of electronic
transitio gives rise to this color? EXPLAI your reasoning.
r: -t /' + I'f) TLeu (pA.e n)2 7 :.> cu -) C -) 0 LC
1\ [Ml'1 CJ 4J ~ t1f1 71- -7 drJ --) L MeT
3) {2 pts} Will Pu{lV} disproportionate to Pu(JlI) and Pu(V) in acidic solutions?
Et> I R) ,s 1\ f f' I 0 ( L-) No. "-' 4) {4 pts} The rate constants for the formation of [CoX(NH3)5]2 from [Co(NH3)61]~ for X= C1, Br", N]', SCN-,
differs by no more than a factor of two. What is the mechanism of substitution7 EXPLAIN your
choice. .1 d+-o r IYI elf) M I" C. IIrJ-C(l1c1Ui5.rOCto.flve. R:-cAle I:> InCfepal It''' 0 ()
5) {4 pts} When [Ni(CN},,]2- is reacted with labeled cyanide, }.4CN', it predominately gives rise to products
that have the formula [Ni(CN4}.(1"CN)y]. where (x+Y) =4. However, there is a very small percentage
of products where (x+y) = 5. What is the mechanism of substitution for [Ni(CN)"t going to
Ni(C~C-4-CN).,l,where (x+Y) =47 EXPlAIN your choice.
one ljLYJAs50cl~hve, (XI J) ~S ~ 1'1 f rf410,tJ. Ie.. L/ -('&(/ y-dlrt:lIe
Is,la!e... . If Is fJu. Y-,vl-x" 41st)
fe-no! ~. t~ a....
6) {14 pts} Using ligand Field Theory. complete the a MO diagram of a complex with tetrahedral symmetry,
a. lid _r _a
b. i z .::: dX:.J I dlJ C ) c1Z: 'f:
c. e. -= dz.'2 , dX7 -j'2.I-~ = Px.{>y-P:! II ~ _~ - -.rt:'I. d·4
III ,....".' ~ n-} p - _ ~~~':' ". e.
I:. ~,.,_,,~-'~'~;:'~:,.,-?(_.:,-, ". i.~ :I f. -L 2
",.,::\:.<r'~ -, - -,':' ~<; G) _ ~ _ ~ _~;:.._~.~ __....-- _fh:=t _---...., __ CAl
"';'" ~ /"': I l g,
L~ U .....\'.,'. ...,-.'I '..,.,... " I h. e ~ I \\ (il--'J' f~ ~ GJ '\" .:' ~ i. CA~
'. .'---'..: j. l1.~
k. \.: t I) s 7) {I pt} Draw a box around the orbitals considered by CFT.
8) flO pts} Design a two-step syntheses for the ds- and trons- [PtzOz(CO)(NH3U2- starting from [PtCL.t.
Co ') C\ "> N~3
CO .... cO \")0 /L.I ---=;> P -0/Jl .... CJ /
1 ( I CI
Cl (0/Cl N~~ "t-l ~ C\ /NPL ---;> f{ --) fl csC,
/ tl / C, /' to CII
9} {S pts} Calculate the value of E" for the PUOl2 !Pu couple in aqueous acidic solutions.
~l\.()31 f'1(-1.2;)
b
--
10) {9 pts} Assign an outer- or inner-sphere mechanism for each of the following. EXPLAIN your choice.
a. The main product of the reaction between [Cr(H20)~ (NCS)FJ'" and [Cr(H20)&!2- is [Cr(H20)sF] 2~.
T ",nea-- -sphort. L\~a.(Jd coot -hoos-\c.rr d
b. When [VO(edta))2- reacts with [Vot. a transient red color is observed.
T,., 1'1 't(,- ~p/...u~ 1 (C\ 1'1 $1 e n~ r d color -:-- -r ("QI'1 s,,\"1 ~n c\ (\\
C- () Y¥l 'P Ie.)(.
c. The rates of reduction of [Co(NHV5PY]~by [Fe(CN)6}3- are insensitive to substitution of py.
Ovh'f - SP~f e. r~ S u 5+' t-U+IO n 1-V6uld e-.f+eet br\d~ toy 0. Ie n ,
j 'Yl (~ ,~ does ~ \~ 1 no bn "1 tof P'lC'.d
11) {6 pts} Calculate the cell emf produced by a fuel cell that combines hydrogen with oxygen under
standard conditions. H ~ J. l f 02. --, 2 Hl 0
EO::::. 0d...j.. ( Hz. ~ 2H+ ae- ) EO: 1,~~9v
°l + 4 H+ + 4 e- -7 H2 O
E~ \. ':l;}qv
12) {S pts} On the Ellingham diagram below, mark on the temperature axis the lowest temperature at
which the metal oxide can be reduced to metal by carbon. What is the overall reaction at this
temperature?
M o· r G (Co
Temperature
0)
13) {12 pts} Use the diagrams of the primitive cubic unit cell shown on the right. (Be
careful when calculating an edge -look at where the spheres are touching and
where they are not - this is different from the closed packed one we covered.)
a. Calculate the number of atoms in the unit cell.
c. What is the "coordination number" of the atoms in the solid? In other words how many atoms
is each atom touching?
14) {12 pts} Use the diagram of a zinc sulfur unit cell shown on the right.
a. Calculate the formula unit.
s: Zn :
b. How many formula units are in the unit cell?
c. This unit cell can be viewed as an expanded btUle-=o,-,-n.l...:a..~\ dosed packed unit cell in 52
with Zn?4 in JoHhe -1 e.trqhedru 1_ holes.
15) {2 pts} The species depicted in the Frost diagram will tend to go under what kind of reaction?
+0
80 US:
1) {2 pts} What is the name of the crystal structure in question 14?
Wurtzxre.. 2) {S pts} Using the grid below, construct a Frost diagram for plutonium(O) to plutonium(IV). Be sure to
label your axes.
oj \c\6.~ 10Yl :5k..h:. S- ·n \;0-, U
0 0- I 0
-L
----.. -1
~ -3 lLJ C -l.{
-5
3
~ -1,1 '-;J t Y -~ - ~ IdD
-1 1 2; -5 Ll
Y
o 1 5 ~ O;(lda\'lo" flutnbe..r
3) {3 pts} Common glass used for windows and bottles appears colorless, but when viewed through
the edge it appears faintly green. Fe3- causes the color. Why it is so faintly colored and why does
looking at the edge reveal the C lor? Irl f C (!L. S C 1 f'r c 1Ci. I jd-d +raYlSlf,On 1101 as J M"",I,
nl d II/crt ~J~S pall, ;, roO -' hfJh Sf ll'7. vlruJ 'ng On ~
fAvs aosorp 1-10 n
II ~ £. b c 1