k = 1.3807 x 10-23 J K-1
R = 0.082057 l atm mol-1 K-1
= 8.314 J mol-1K-1
= 1.987 cal mol -1 K-1
= 8.314 V C mol-1 K-1
k = R/NA
NA = 6.022 x 1023 mol-1
1 kcal = 4.184 kJ
c = 2.998 x 108 m s-1
c = λν
E = -13.6(Z/n)2 eV
1 eV = 1.6022 x 10-19 J
1 eV = 96.485 kJ mol-1
E = hν
χ = (IE+EA)/2
ΔE = -2.18 x 10-8 J (Z2) (1/n2f - 1/n2i)
E = -me4Z2/8εon2h2
E= mc2
λ = h/mv
1 nm = 10-9 m
1 D = 10-8 cm=100 pm
εo = 8.85 x 10-12 J-1C2m-1
4πεo = 1.113 x 10-10C2J-1m-1
U % NAq+q-e2M/ro
ΔG = ΔH - TΔS = -RTlnK
ΔGE = -nF EE
RT [products]
E = Eo −
ln
nF [reactants]
M
M
M
I– < Br– < Cl– < SCN– < F–, OH– < NO2– < H2O < SCN– < NH3 < en < NO2–
< PR3 < P(OR)3, C2H4< PF3, H&, CH3&, CO, CN–
F*
np
F*
B*
p
F*
ns
eg*
)
(n-1) d
F
E
B
F*
s
t2g
F
n
F
L orbitals
F
F
F
p
s
First Name____________________Last Name____________________________
Chem 1311
Fourth Exam
26 November 2008
In taking this examination, you are expected to adhere to the GT academic honor code. At a
minimum this requires that you utilize only the materials supplied to you, and that you do not
give help to, or accept help from, others. Calculators and other electronic devices are not
allowed.
1. (14) Draw all diastereoisomers of the six-coordinate Co(III) complex [Co(NH2CH2CH2S)2(NH3)2]+.
Indicate those isomers that are optically active (have non-superimposible mirror image forms) by drawing
a box around the structure. You may abbreviate the chelating ligand as SÒN in making your drawings.
Careful - points will be deducted for each duplicate structure and incorrect indication of a structure as
optically active.
S
2. (3) What is the average oxidation state for iron the in the model of the
4-Fe-4-S electron transfer cluster shown to the right? __________
(3) How many unpaired electrons would iron have in this coordination
environment when its oxidation state is +3? ______
PhCH2
S
S
S
1-
Fe
Fe
CH2Ph
S
Fe
CH2Ph
S
Fe
S
S
CH2Ph
3. (75 - 5 pts each) Circle the letter corresponding to the correct answer.
The complex ions [NiCl4]2& is paramagnetic (has unpaired electrons) whereas ZnCl42& is diamagnetic.
Based upon this information, which of the following statements concerning their structures is correct?
a) Both compounds have a tetrahedral arrangement of ligands around the metal
b) Both compounds have a square planar arrangement of ligands around the metal
c) It is impossible to determine the stereochemistry of either species on the basis of its magnetism
d) The nickel complex has a tetrahedral arrangement of ligands around the metal
Which of the following species will have the largest crystal field splitting?
a) CoF64&
b) CoF42& (tetrahedral)
c) CoCl64&
d) CoCl42& (tetrahedral)
Which coordination complex should have the smallest number of unpaired electrons (cyanide is a strong
field ligand)?
a) [Cr(CN)6]3&
b) [Mn(CN)6]3&
c) [Fe(CN)6]3&
d) [Co(CN)6]3&
In the deoxygenated form the dinuclear copper oxygen carrier hemocyanin has both copper ions in the
+1 oxidation state. Upon oxygenation both copper ions are in the +2 oxidation state. Which of the
following is the best description of the coordinated O2 moiety?
a) O22+
b) O2
The structures shown to the right are?
a) constitutional (structural) isomers
b) diastereoisomers (geometric isomers)
c) enantiomers
d) none of the above
d) O22&
c) O2&
Cl
Cl
Cl
Co
NH3
NH3
H3N
NH3
Cl
NH3
Co
Cl
NH3
Cl
Name ________________________________________
As a ligand to transition metal ions, H2O is
a) a σ donor only
b) both a σ donor and π donor
c) both a σ donor and π acceptor
d) none of these
Which ion will be most reactive toward ligand substitution/exchange?
a) [Fe(OH2)6]2+
b) [Fe(OH2)6]3+
c) [Ru(OH2)6]2+
d) [Ru(OH2)6]3+
Which of the following species is expected to bond with a transition metal ion only as a σ donor, i.e., no
π donor or acceptor capability.
a) B(CH3)3
b) C(CH3)31–
d) none of these
e) all of these
c) P(CH3)3
Which of the following compounds has the transition metal ion in the highest oxidation state?
a) K4[Fe(CN)6]
b) [NH4]2[ReH9]
c) Na2[WO4]
d) [Pt(NH3)6]Cl4
For which of the following reactions will the product undergo the greatest increase in bond distance (CN&
is a strong field ligand; OH2 is an intermediate field ligand?
a) [Mn(CN)6]3& + e– ÷ [Mn(CN)6]4&
b) [Mn(OH2)6]3+ + e– ÷ [Mn(OH2)6]2+
c) [Mn(CN)6]4& ÷ [Mn(CN)6]3& + e–
d) [Mn(OH2)6]2+ ÷ [Mn(OH2)6]3+ + e–
For which of the following compounds is the absorptivity of a 0.1 M solution expected to be lowest?
a) [Mn(OH2)6]2+
b) [Fe(OH2)6]2+
c) [Mn(CN)6]4&
d) [Fe(CN)6]4&
Shown below are electronic spectra for [Ti(OH2)6]3+ and [TiCl6]3& recorded as a function of inverse
wavelength, which is proportional to energy.
a)
spectrum (1) is due to [Ti(OH2)6]3+ because the ligand field
splitting due to water is greater than for Cl&
b)
spectrum (1) is due to [Ti(OH2)6]3+ because the ligand crystal
field splitting due to water is less than for Cl&
c)
spectrum (2) is due to [Ti(OH2)6]3+ because the ligand field
splitting due to water is greater than for Cl&
d)
spectrum (2) is due to [Ti(OH2)6]3+ because the ligand crystal
field splitting due to water is less than for Cl&
(1)
(2)
Which of the following complex ions is least likely to absorb in the visible region of the electromagnetic
spectrum?
a) [ScCl6]3–
b) [TiCl6]3–
c) [VCl6]3–
d) all absorb in the visible region
Which of the following complex ions is most likely to be low spin?
a) [FeCl6]4–
b) [Fe(OH2)6]2+
c) [Fe(CN)6]4–
d) all are high spin because they are
iron(II) from the first transition series
Which of the following reactions will have the largest equilibrium constant?
a) [Ni(OH2)6]2+ + 2 NH3 = [Ni(OH2)4(NH3)2]2+ + 2 H2O
b) [Ni(OH2)6]2+ + NH2CH2CH2NH2 = [Ni(OH2)4(NH2CH2CH2NH2)]2+ + 2 H2O
c) [Ni(OH2)4(NH3)2]2+ + 2 H2O = [Ni(OH2)6]2+ + 2 NH3
d) [Ni(OH2)4(NH2CH2CH2NH2)]2+ + 2 H2O = [Ni(OH2)6]2+ + NH2CH2CH2NH2
4. (6) Name two biologically active transition metal containing compounds, indicate their biological role,
and the metal ion involved in each.
Compound
Function
Metal ion