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Exam 1
Chem 222
Name ________________
January 10, 2014
SHOW YOUR WORK. NO WORK, NO CREDIT
INCLUDE LABELS AND PROPER NUMBER OF SIG FIGS
Up to 75% of the credit for a problem will be given for correctly setting it up, including labels on all numbers.
On my honor, I pledge that I have upheld the Honor Code, and that the work I have done on this assignment has been
honest, and that the work of others in this class has, to the best of my knowledge, been honest as well.
Signed _________________________________________________________________
If you feel you can’t sign this, contact the instructor (email, or in person)
Silver Group: Ag, Hg, Pb
Aluminum-Nickel Group: Ni, Fe, Co, Mn, Al, Cr, Zn
Copper-Arsenic Group: Cu, Hg, Pb, As, Sb, Bi, Sn, Cd
Barium-Magnesium Group: Na, K, Mg, Ca, Ba, NH4+1
Circle the correct answer. (multiple choice = 2 pts. Each)
1.
What is the number of radial nodes in a 4s orbital?
a) three
b) four
c) two
d) zero
2. What are the possible values of l if n = 5?
a) -5, -4, -3, -2, -1, 0, +1, +2, +3, +4, or +5
b) 5
c) +5 or -5
d) 0, 1, 2, 3, or 4
3. The spheres below represent atoms of Li, Be, B, and F (not necessarily in that order). Which one of these spheres represents an atom of B (boron)? (a)
(b)
(c)
(d)
4. Which orbital can form a pi-bond with a pz orbital?
a) s
b) pz
c) py
2
d) dz
e) none of the above
5. How many unpaired electrons are in an atom of Co in its ground state? a) 1
b) 2
c) 3
d) 4
e) 5
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6. Which of the following states “Electrons must be arranged in a subshell to give the maximum number of electrons of the same
spin”?
a) Pauli exclusion principle
b) shielding effect
c) Hund’s rule
d) Aufbau principle
Which of the orbitals to the right represents the dyz orbital?
7.
(a)
(b)
(c)
(d)
-
8.
What is the molecular geometry (shape) of the nitrate ion, NO3 ?
a)
b)
c)
d)
trigonal bipyramidal
trigonal pyramidal
tetrahedral
trigonal planar
9.
a)
b)
c)
d)
e)
The Lewis dot structure for SF4 shows
a total of 32 electrons
4 single bonds and 10 lone pairs
2 single bonds, 2 double bonds, and 10 lone pairs
1 single bond, 2 double bonds, and 8 lone pairs
1 lone pair on the sulfur atom and 3 lone pairs on the fluorines
+
10. In the best Lewis structure for NO , what is the formal charge on the N atom?
a) 0
b) +1
c) -1
11. Which two orbitals will have the best overlap?
a) N(2s) and O(2s)
b) N(2s) and O(2p)
c) N(2p) and O(2s)
d) N(2p) and O(2p)
d) +2
e) -2
(N(2s) = -25.56 eV, N(2p) = -13.18 eV O(2s) = -32.38 eV, O(2p) = -15.85 eV)
12. Which chemical will have the smallest bond angles?
a) OCl2
b) SCl2
c) SeCl2
d) TeCl2
13. Which ion will form a precipitate with (NH4)2S (aq)?
a) Na+1
b) Cd+2
c) Al+3
d) Ag+1
14. Which reagent will differentiate between solid Pb(NO3)2(aq) and Hg(NO3)2 (aq)?
a) 6 M HCl (aq)
b) conc H2SO4 (aq)
c) hot H2O
d) HNO3 (aq)
15. Which is the group reagent for the Cu-As group?
a) conc. NH3 (aq)
b) cold 6 M HCl (aq)
c) (NH4)2S (aq)
2
d) 3 M HNO3 (aq)
16. a) PCl5
i) (4 pts.) Draw the best Lewis dot structure of PCl5. Also, draw the 3-dimensional shape of PCl5 - use dashes and wedges to
indicate spatial geometry.
ii) (1 pt.) What is the electron-pair geometry of PCl5? ____________________________________
iii) (1 pt.) What is the molecular shape of PCl5? ____________________________________
iv) (1 pt.) What are the approximate bond angles in PCl5? ____________________________________
v) (1 pt.) Is PCl5 polar or non-polar? _______________________
-
b) ClO3
(4 pts.) Draw the best Lewis dot structure of ClO3-. Also, draw the 3-dimensional shape of ClO3- - use dashes and wedges to
indicate spatial geometry.
17. Calculate the total pairing energies for the two five d-orbital electron configurations below.
i) (2 pts.)  
ii) (2 pts.)  
__ __
 
 = __________
 = __________
iii) (2 pt.) Which of the above electron arrangements is the most stable (circle one)? i) or ii)
iv) (2 pts.) Explain why you made your choice in iii).
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18. a) (4 pts.) Calculate the effective nuclear charge for the outermost electron of a zirconium (Zr) atom. Circle your final answer.
b) (4 pts.) Calculate the effective nuclear charge for the outermost electron of a ruthenium (Ru) atom. Circle your final answer.
c) (2 pts.) Which will have a smaller radius, Zr or Ru? ______
19. (6 pts) Cold dilute hydrochloric acid added to a silver group unknown produced a white precipitate. This precipitate was
completely soluble in concentrated ammonia. Which ions were present? Absent? Undetermined? Explain your reasoning.
20. (16 pts) H2S is bubbled through a Cu-As group unknown and a black precipitate forms. (NH4)2S is added and the black precipitate
remains. The decantate “A” is set aside for further testing. The black solid is reacted with HNO3 to give a colorless solution, which is
then reacted with H2SO4, giving a white precipitate. The decantate from this precipitate is then reacted with KCN, followed by
(NH4)2S (aq), which results in a yellow solid.
Decantate “A” is treated with concentrated HCl, which first produces an orange precipitate, then with more HCl the solid completely
dissolves.
Which ions are present? Absent? Undetermined? Explain your reasoning.
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21. a) (8 pts.) Complete the molecular orbital diagram for neutral dicarbon, C2, filling all the electrons in the appropriate molecular
orbitals. Show only the 2s and 2p interactions. (hint: the s and p orbital arrangement is like that of N2)
b) (2 pts.) Label the molecular orbitals as  or ( or ).
c) (2 pts.) Indicate on your drawing above which orbitals are the HOMO and LUMO.
C
MO
C
d) (2 pts.) By your MO diagram, is C2 paramagnetic or diamagnetic? ______________________
e) (2 pts.) By your MO diagram, what is the bond order for C2? _________________
f) (2 pts.) Which is more stable, C2
+2
-2
or C2 ? ___________
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Exam 2
January 17, 2014
Chem 222
Name ________________
SHOW YOUR WORK. NO WORK, NO CREDIT
INCLUDE LABELS AND PROPER NUMBER OF SIG FIGS
Up to 75% of the credit for a problem will be given for correctly setting it up, including labels on all numbers.
On my honor, I pledge that I have upheld the Honor Code, and that the work I have done on this assignment has been
honest, and that the work of others in this class has, to the best of my knowledge, been honest as well.
Signed _________________________________________________________________
If you feel you can’t sign this, contact the instructor (email, or in person)
Silver Group: Ag, Hg, Pb
Copper-Arsenic Group: Cu, Hg, Pb, As, Sb, Bi, Sn, Cd
Aluminum-Nickel Group: Ni, Fe, Co, Mn, Al, Cr, Zn
Barium-Magnesium Group: Na, K, Mg, Ca, Ba, NH4+1
Circle the correct answer. (multiple choice = 2 pts. Each)
1. The following pictures represent equal volumes of aqueous solutions of three acids HA (A = X, Y, or Z); water molecules have
been omitted for clarity. Which acid is the weakest?
= HA
X
A. X
2.
C. Z
= H+
Y
Z
D. all three are weak acids so they are the same strength
A superacid is any acid that is stronger than _______.
A. HNO3
3.
B. Y
= A-
B. H3O+
C. H2SO4
D. HCl
Which of these species is a base when dissolved in water?
A. NaCl
B. H2SO4
C. CaO
D. Co+3
C. PbI2
D. PbS
4. Which compound is the most soluble in water?
A. PbCl2
B. PbBr2
5. Which of the following is NOT a Brønsted-Lowry acid?
A. BBr3
B. CH3COOH
C. HCl
D. HCN
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6. Which base is the strongest?
A. NH3
B. PH3
C. SbH3
7. The most efficient packing structure is ________.
A. simple cubic
B. hcp
C. fcc
8. The coordination number around each atom in a simple cubic lattice of a metal is
A. 2
B. 4
C. 6
D. 8
E. 12
9. A binary ionic compound, MxAy, crystallizes in a cubic structure that contains eight anions (A) entirely within its unit cell and a
cation (M) on each corner and on each face. What is the empirical formula of this compound?
A. MA
B. M2A
C. MA4
D. MA2
10. Which solid imperfection has an atom of similar size added into the bulk solid?
A. vacancy
B. interstitial
C. substitution
D. dislocation
11. Which material’s conductance increases with increasing temperature?
A. insulator
B. metallic conductor
C. semiconductor
D. superconductor
12. Which element would turn silicon into a n-type doped semiconductor?
A. Al
B. Ge
C. P
D. B
13. You are handed your Ni-Al unknown and it is pink. Which ion is present?
A. Zn+2
B. Co+2
C. Ni+2
D. Fe+3
14. Which aqueous reagent will form a precipitate with Fe+3 and not with Co+3?
A. (NH4)2S
B. excess HCl
C. excess NH3
D. excess NaOH
15. Which ion’s observation is assisted by the creation of a “lake”?
A. Al+3
B. Fe+3
C. Zn+2
D. Mn+2
16. Which element does NOT form a blue solution or solid at some point within the qual schemes?
A. Co
B. Ba
C. Mg
D. Cr
17. Which ion was determined using litmus paper?
A. Ca+2
B. Na+
C. Mg+2
D. NH4+
2
18. (8 pts.) A solution of Ba(OH)2(aq) has a molarity of 0.142 M. Calculate the [H3O+] and pH of this solution.
19. (8 pts) The pKa of HCN is 9.31. What is the pH of a 0.521 M solution of HCN? Figure 1- see projector screen
20. a) (2 pts) How many total purple atoms are there within the unit cell? ___________
b) (2 pts) How many total green atoms are there within the unit cell? _____________
c) (2 pts) What is the most likely compound for this unit cell? (circle one)
a) Na2O
b) KBr
c) TiO2
d) FeBr3
d) (2 pts) Which structure does this unit cell resemble?
a) NaCl
b) wurtzite
c) TiO2(rutile)
d) antifluorite
e) (2 pts) What is the coordination number of the purple atoms? __________
f) (2 pts) What is the coordination number of the green atoms? __________
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21. (6 pts) A certain metal crystallizes in a face-centered cubic structure. What is the edge length of the unit cell if the atomic radius
of the metal is 144 pm?
22. (10 pts) Rhodium has a face-centered cubic structure and has a density of 12.4 g/cm3. What is the volume of the unit cell in pm3?
(1 pm = 1x10-10 cm).
23. (8 pts) Draw the band structure of a metallic conductor. Label conduction band, valence band, band gap and fill in appropriate
electrons.
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24. (14 pts) A pale green Al-Ni group unknown was divided into two parts.
a. To one part NaOH was added, slowly with constant stirring. A green precipitate formed. Part of the solid re-dissolved with an
excess of NaOH. The solution was centrifuged and decanted. The colorless decantate was treated with first HNO3, then NH3, then
BaCl2 and no precipitate was observed upon any of those additions.
b. One part was treated with NH4Cl and excess NH3 and gave a blue solution with no precipitate.
Which ions are present? absent? undetermined? Explain your reasoning. (see beginning of test for all elements in Al-Ni group)
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Exam 3
January 24, 2014
Chem 222
Name ________________
SHOW YOUR WORK. NO WORK, NO CREDIT
INCLUDE LABELS AND PROPER NUMBER OF SIG FIGS
Up to 75% of the credit for a problem will be given for correctly setting it up, including labels on all numbers.
On my honor, I pledge that I have upheld the Honor Code, and that the work I have done on this assignment has been
honest, and that the work of others in this class has, to the best of my knowledge, been honest as well.
Signed _________________________________________________________________
If you feel you can’t sign this, contact the instructor (email, or in person)
Silver Group: Ag, Hg, Pb
Aluminum-Nickel Group: Ni, Fe, Co, Mn, Al, Cr, Zn
Copper-Arsenic Group: Cu, Hg, Pb, As, Sb, Bi, Sn, Cd
Barium-Magnesium Group: Na, K, Mg, Ca, Ba, NH4+1
-1
-1 -1
-1
-3
-3
-1
Anions: C2H3O2 , AsO4 , BO3 or BO2 , Cl , Br , I , S-2, PO4-3, CrO4-2, CO3-2, SO3-2, SO4-2, NO3-1
R = 8.314 J mol1 K 1 = 0.0821 Latmmol1 K 1
F = 96500 Cmol1 = 96500 J V 1  mol1
N A = 6.022 x 1023 mol1
c = 2.998 x 108 ms1
h = 6.626 x 1034 Js
 Ea
0°C = 273.15 K
12
M 
rateA
= B
rateB
 MA 
RT
0.05916
Nernst Equation: E = E° ln(Q) Nernst Equation at 25°C: E = E° ln(Q)
nF
n
1
1
Integrated Rate Laws zero: [A] = [A]0 - kt first: ln[A] = ln[A]0 - kt
second:
= kt +
[A]
[A]0
Arrhenius Equation: k = Ae
RT
Graham's Law of Effusion:
Circle the correct answer. (multiple choice = 2 pts. Each)
1. How many 3d electrons does a Cu2+ ion have?
A. 2
B. 7
C. 8
D. 9
E. 10
2. In the coordination compound K2[Co(en)Cl4], the coordination number (C.N.) and oxidation number (O.N.) of cobalt are
A. C.N. = 6; O.N. = +2.
B. C.N. = 6; O.N. = +3.
C. C.N. = 5; O.N. = +2.
D. C.N. = 5; O.N. = +4.
3. Which definition best describes isomers that are non-superimposable mirror images of each other that rotate plane polarized light to
the same degree but in opposite directions?
A. linkage isomers
B. diastereoisomers
4. Which ion has cis and trans isomers?
A. [Pt(CN)5NH3]-
C. ionization isomers
B. [Pt(C2O4)2]2-
D. enantiomers
C. [PdCl3NH3]-
D. [PtCl2(CN)2]2-
5. What is the first row transition metal M for the compound [M(NH3)6]+2 and has a spin magnetic moment of 4.90 Bohr magnetons?
A. Ti
B. V
C. Cr
D. Mn
E. Fe
6. Which of the following species is diamagnetic?
A. a low-spin octahedral Co3+ complex
B. a high-spin octahedral Fe2+ complex
C. an isolated, gas-phase Cu2+ ion
D. an isolated, gas-phase V3+ ion
1
7. Which isomer of Co(en)33+ is shown to the left?
A. 
B. 
8.
What is the shorthand notation that represents the following galvanic cell reaction?
2 Fe2+(aq) + Cl2(g) → 2 Fe3+(aq) + 2 Cl-(aq)
a) Pt(s) ∣ Fe3+(aq), Fe2+(aq), Cl2(g) ∣∣ Cl-(aq) ∣ Pt(s)
b) Pt(s) ∣ Fe2+(aq), Fe3+(aq) ∣∣ Cl2(g) ∣ Cl-(aq) ∣ Pt(s)
c) Fe(s) ∣ Fe2+(aq) ∣∣ Fe3+(aq) Cl2(g) ∣ Cl-(aq) ∣ Pt(s)
d) Fe2+(aq) ∣ Fe3+(aq) ∣∣ Cl2(g) ∣ Cl-(aq)
9.
What is the reduction half-reaction for the following overall cell reaction?
Ni2+(aq) + 2 Ag(s) → Ni(s) + 2 Ag+(aq)
a. Ni2+(aq) + e- → Ni(s)
b. Ag(s) + e- → Ag+(aq)
c. Ni2+(aq) + 2 e- → Ni(s)
d. Ag+(aq) + e- → Ag(s)
10. The overall reaction 2Co3+(aq) + 2Cl-(aq)  2Co2+(aq) + Cl2(g) has the standard cell voltage Ecell = 0.46 V. Given that
Cl2(g) + 2e-  2Cl- (aq), E = 1.36 V, calculate the standard reduction potential for the following the half reaction at 25C:
Co3+ + e-  Co2+
A. 1.82 V
11.
A.
B.
C.
D.
B. -0.90 V
C. 0.90 V
D. -1.82 V
Which is not true for standard electrode potentials? Cell constituents are in their standard states. The half‐reactions are written as reductions. The potential for the standard hydrogen electrode is chosen to be +1.00 V. E° for oxidation is the negative of E° for reduction. 12. Consider the following table of standard half-cell potentials:
A2 + 2 e– → 2 A–
E° = + 1.09 V
B4+ + 2 e– → B2+
E° = + 0.15 V
3+
–
C +3e →C
E° = – 1.66 V
D2+ + 2 e– → D
E° = – 2.37 V
Which substance is the strongest oxidizing agent?
A. A2
B. B4+
C. C3+
D. D2+
13. What is the relation between ΔG° and E° for the cell reaction below?
Ni2+(aq) + Cd(s) → Cd2+(aq) + Ni(s)
A. ΔG° = 2 F E°
B. ΔG° = -2 F E°
C. ΔG° = F E°
D. ΔG° = -F E°
14. Based on the following three reduction half reactions, which reaction in the list will be spontaneous?
Cu2+(aq) + 2e-  Cu(s) Eo = 0.337V
Al3+(aq) + 3 e-  Al(s) Eo = -1.66V
Na+(aq) + 1e-  Na(s) Eo = -2.714V
A. 2Na+(aq) + Cu(s) Cu2+(aq) + 2Na(s)
B. Al(s) + 3Na+(aq)  Al+3(aq) + 3Na(s)
C. 2Al(s) + 3Cu(s) 3Cu2+(aq) + 2Al+3(aq)
D. 2Al(s) + 3Cu+2(aq) 3Cu(s) + 2Al+3(aq)
2
15. Which anion gives a green flame test?
A. PO4-3
C. Cl-
B. CrO4-2
D. BO2-
16. Which reagent would help you distinguish between K3AsO4 and CdSO4?
A. NO3-
B. NH4+
D. Ag+
C. C2H3O2-
17. Which anion bubbles when added to acid?
A. CO3-2
B. C2H3O2-
C. SO4-2
D. AsO4-3
18. (3 pts each) Name the following compounds:
[Ni(en)(CN)2]
____________________________________________
[Co(H2O)4Cl2]Br ____________________________________________
19. (3 pts each) Write the formula for the following compounds:
Tetraamminedinitrochromium (III) sulfate
____________________________________________
Sodium bis(2,2’-bipyridine)dichloroaurate(I)____________________________________________
20. (10 pts) Draw the picture of the galvanic cell made from electrodes consisting of the half reactions Al+3(aq) + 3e-  Al(s) E° =
-1.66 V and Co+2(aq) + 2e-  Co(s) E° = -0.277 V. Assuming the reaction is spontaneous and a salt bridge with NaNO3, label the…
a) anode and cathode, including all reactants and products that are contained within those electrodes
b) the direction of the electron flow through the wire
c) the direction of the anion and cation flow through the salt bridge
21. (8 pts) How many grams of nickel metal are plated out when a constant current of 15.0 A is passed through aqueous NiCl2 for
60.0 minutes? (1 e- = 1.6022x10-19 C)
3
22. (8 pts) Calculate the Ecell for the following reaction at 25C: Fe(s) ∣ (Fe2+(0.100 M) ∣∣ Pd2+(1.0 × 10-5 M) ∣ Pd(s).
The standard reduction potential for Fe2+/Fe is -0.45 V and for Pd2+/Pd is +0.95 V.
23. (6 pts) Draw all the stereoisomers for the octahedral [FeF3Cl3]-3 complex ion. How many total stereoisomers are there? How
many enantiomer pairs are there? (Use wedges and dashes in your structures to indicate 3-dimensional structure). Duplicate
structures will be counted against you.
Total # of stereoisomers = _________
# of pairs of enantiomers = _________
4
24. (10 pts) Balance the following redox reaction that takes place in acidic solution.
OBr- +
HPO3-

Br- +
PO4-3
25. (12 pts) A solid mixture was known to contain two or more of the following compounds: silver nitrate, sodium arsenate, cobalt(II)
nitrate, bismuth chloride, cadmium nitrate, and zinc acetate.
The mixture dissolved completely in cold water to give a clear, colorless solution. Addition of excess ammonia did not change the
appearance of the solution.
Addition of a second sample of the solid to dilute hydrochloric acid produced a white precipitate.
Which compounds are present? Absent? Undetermined?
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