Practice Exam 3 – Bonding and Coordination Chemistry
Useful Information
Spectrochemical Series
Strong Field
Weak Field
CN- > -NO2- > en > NH3 > H2O > OH- > Cl- > IMultiple Choice (2 points each)
_____1. Carbon uses ______ hybrid orbitals in ClCN.
A) sp
B) sp2
C) sp3
D) sp3d
-
_____2. Valence bond theory predicts that tin will use _____ hybrid orbitals in SnCl3 .
A) sp
B) sp2
C) sp3
D) sp3d
_____3. Valence bond theory predicts that xenon will use _____ hybrid orbitals in XeOF4.
A) sp2
B) sp3
C) sp3d
D) sp3d 2
_____4. The ground state electronic configuration of Cr3+ is
A) [Ar]4s13d 5
B) [Ar]4s23d 4 C) [Ar]3d 3 D) [Ar]4s13d 3
E) [Ar]4s23d 2
_____5. Which of the following ions is most likely to form colored compounds?
A) Sc3+
B) Cu+
C) Zn2+
D) Cr3+
_____6. What is the coordination number of cobalt in the complex ion [Co(en)Cl4]-? (en =
ethylenediamine)
A) 1
B) 2
C) 4
D) 5
E) 6
_____7. In the compound K[Co(C2O4)2(H2O)2] (where C2O42- = oxalate) the oxidation number
and coordination number of cobalt are, respectively:
A) -1 and 4
B) -1 and 6
C) 3 and 4
D) 3 and 6
E) 1 and 6
_____8. Choose the correct name for the formula, [Cr(NH3)4(OH)2]Br
A) chromium(II) tetraamminebis(hydroxo) bromide
B) chromium(III) tetraamminebis(hydroxo) bromide
C) tetraamminedihydroxochromium(II) bromide
D) tetraamminedihydroxochromium(III) bromide
_____9. Choose the correct name for the formula, [Co(en)3][Cr(ox)3].
and ox = C2O42-, oxalate
A) tris(ethylenediamine)cobalt(III) tris(oxalato)chromium(III)
B) tris(ethylenediamine)cobaltate(III) tris(oxalato)chromate(III)
C) tris(ethylenediamine)cobalt(III) tris(oxalato)chromate(II)
D) tris(ethylenediamine)cobalt(III) tris(oxalato)chromate(II)
en = ethylenediamine
_____10. The complex of Ni2+ with DMG (dimethylgloxime), Ni(DMG)2, has the structure:
H
O
O
N
N
H3C
What is the geometry shown around the central
atom?
A) linear
B) bent
C) tetrahedral
D) trigonal bipyramidal
E) distorted tetragonal F) octahedral
G) square planar
CH3
Ni
H3C
N
N
O
O
CH3
H
_____11. How many coordinate covalent bonds to a central metal atom can the following
chelate (called Porphyrin2–) form?
A) 1
B) 2
C) 3
D) 4
E) 5
F) 6
N not determine
N
G) can
N
N
_____12. Which of the following is not an example of a set of isomers?
Cl
H3N
H3N
Co
Cl
NH3
NH3
vs.
H3N
H3N
Cl
A)
H3N
Zn
. H3N
Cl
vs.
H3N Zn
Cl
Cl
SCN
H3N
H3N
C)
Co
NH3
Cl
NH3
Cl
B)
Co
NH3
NCS
NH3
NH3
vs.
NH3
D) all of these are sets of isomers
H3N
H3N
Co
NH3
NH3
NH3
_____13. What is the coordinate number for the central atom in [Co(en)(NH3)3Cl]SO4?
A) 2
B) 3
C) 4
D) 5
E) 6
F) 7
G) 8
H) 10
_____14. The anti-cancer drug cis-platin has the formula Pt(NH3)2Cl2. There is another
isomer, tans-platin, that is not medically active. What is the shape of cis-platin?
A) linear
B) tetrahedral
C) octahedral
D) square planar
E) trigonal bipyramidal
_____15. Which of the following is most likely to be a low spin complex? Answer all
that apply.
A) [FeF6]3– B) [Pt(CN)6]2–
C) [MnF3Cl3]4–
D) [Zn(CN)4]2–
16. (6 pts) Given the molecule shown below, which of the labeled bonds will have free
rotation about that bond and which will not? You will lose points for any incorrect
identifications.
H
H
C
H
e
O
C
C
C
C
O
d
c
C
H
C
CH3
b
C
C
f
H
C
a
H
H
CH3
H
______
Identify the bond(s) that can freely rotate in the blank to the left.
______
Identify the bond(s) that do not freely rotate in the blank to the left
17. (10 pts) Draw all isomers for the compound [Fe(en)Cl2F2]–. Label and prove any
isomers that are optically active.
18. (11 pts) Use the following Molecular Orbital Diagram to answer this question to
show the arrangement of electrons for NO.
_____
2p*
*
_____
_____
2p
_____
2p
_____
_____
2p
*
_____
2s
_____
2s
A) Complete the following table.
NO+
NO
Bond Order
Spin
Paramagnetic (P) or Diamagnetic(D)
B) List the three species, NO, NO+, NO-, from smallest bond energy to largest bond
energy:
Smallest Bond Energy
Largest Bond Energy
<
<
19. (10 pts) Identify the hybridization and bond angles for the following atoms on the
molecule:
H b
H
Oe
C
Cg
Oh
c
C
a
Cf
H
H
d
C
C
O
H
C
H
Bond Angles
Hybridization
a) ______________
e) Oe ______________
b) ______________
f) Cf ______________
c) ______________
g) Cg ______________
d) ______________
h) Oh ______________
I) How many  bonds are in this molecule? ________ … bonds in this molecule? _______
20. (6 pts) Show all possible geometric isomers for Cr(NH3)3(OH)3.
21. (9 pts) Use Valence Bond Theory to draw the orbital overlaps for the molecule
CH3COCH3. Your drawing should properly show the 3-D shape of the molecule. Label
each orbital overlap (e.g. sp-sp3)
22. (4 pts) The coordination compound [Cr(NH3)6]Cl3 is yellow and the compound
[Cr(NH3)4Cl2]Cl is violet. Explain this in terms of the crystal field theory.
23. (12 pts) Given the two species acetic acid, CH3COOH, and the acetate ion, CH3COO–. What
is the most appropriate bonding theory to use for O—C—O region in each molecule? Show
drawings/diagrams for each molecule and clearly explain why you selected the theory in each
case. If you use modified molecular orbital theory, draw the lowest energy molecular orbital on
top of the molecule.
Extra Problem- Not on test but covered in section
(8) 28. Co in [CoF6]3- is a high spin complex. Show the distribution of d electrons for
Co3+ in the following octahedral d energy level diagram.
A)
_____
_____
_____ ______ _____
B) The spin on Co ion is _______ and the species is
C) Explain why [CoF6]3- is a colored species.
Paramagnetic OR Diamagnetic
Circle correct answer.