Download chemistry 110 final exam

CHEMISTRY 110 FINAL EXAM
Friday May. 3, 2013
FORM A
-------------------------------------------------------------------------------------1. The highly exothermic thermite reaction, in which aluminum
reduces iron (III) oxide to elemental iron, has been used by railroad
repair crews to weld rails together.
2Al(s) + Fe2O3(s) ! 2Fe(s) + Al2O3(s)
"H = –850 kJ
-------------------------------------------------------------------------------------3. Which of the following reactions is not an oxidation/ reduction reaction?
A. K(s) + 8C(s) ! KC8(s)
B. Li(s) + TiS2(s) ! LiTiS2(s)
C. CO(g) + ! O2(g) ! CO2(g)
D. Cu2+(aq) + Fe2+(aq) ! Cu+(aq) + Fe3+(aq)
E. CaCl2(aq) + 2AgNO3(aq) ! Ca(NO3)2(aq) + 2AgCl(s)
What mass of iron is formed when 725 kJ of heat are released?
A. 47 g
B. 65 g
C. 95 g
-------------------------------------------------------------------------------------4. What is the "Hrxn for CaCO3(s) ! CaO(s) + CO(g) + ! O2(g)
using the following:
D. 112 g
2CO(g) + O2(g) ! 2CO2(g)
"Hrxn = –566.0 kJ
E. 130 g
CaCO3(s) ! CaO(s) + CO2(g)
"Hrxn = 178.1 kJ
-------------------------------------------------------------------------------------2. Molecular equations for five reactions are given below. Which one
will not have a net ionic equation?
A. K2CO3(aq) + 2HCl(aq) ! 2KCl(aq) + CO2(g) + H2O(!)
B. Ca(OH)2(aq) + 2HCl(aq) ! CaCl2(aq) + 2H2O(!)
A. #744.1 kJ
B. #388.0 kJ
C. 128.0 kJ
D. 461.1 kJ
E. 632.1 kJ
C. 2 KCl (aq) + Na2SO4 (aq) ! K2SO4 (aq) + 2 NaCl(aq)
D. Pb(NO3)2(aq) + Na2SO4 (aq) ! PbSO4(s) + 2NaNO3(aq)
E. AgNO3(aq) + KCl(aq) ! AgCl (s) + KNO3(aq)
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-------------------------------------------------------------------------------------5. What is the volume of CO2 collected at 740 torr and 25 oC when
1.25 g CaCO3 is decomposed?
CaCO3 (s) !
CaO (s) + CO2 (g)
-------------------------------------------------------------------------------------7. If the following reaction has Kc = 84.2 at 100 °C:
F2(g) + 2NO (g) ! 2NOF(g)
what is the value of Kc for the following reaction?
A. 0.026 L
NOF(g) ! ! F2(g) + NO (g)
B. 0.152 L
C. 0.314 L
A. 1.18 " 10#2
D. 31.0 L
B. 4.62 " 10#2
2
E. 2.31 $ 10 L
C. 8.65 " 10#2
D. 1.09 " 10#1
-------------------------------------------------------------------------------------6. In coal burning power plants, the following equilibrium is of concern:
E. 8.42 " 10#1
SO2(g) + ! O2(g) ! SO3(g)
due to the reaction of SO3(g) with H2O(g) to form sulfuric acid. What
is the value of Kc if [O2(g)] = 2.85"10#4 M, [SO2(g)]=2.59"10#4 M,
and [SO3(g)]=7.62"10#7 M under equilibrium conditions?
A. 6.97 $10#7
B. 4.97 $10
#5
-------------------------------------------------------------------------------------8. Rank the angles indicated in the molecule below in order of
increasing angle.
1.
A. 1 < 3 < 2
B. 1 = 2 = 3
C. 0.174
C. 2 < 3 < 1
D. 5.74
D. 1 < 2 = 3
E. 10.3
E. 3 < 1 < 2
H
H
H
N
C
C
H
H
H
2.
O
O
C
O
H
3.
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--------------------------------------------------------------------------------9. Which of these molecules has an aldehyde functional group?
O
O
CH3
O
I.
II.
C1
C2
O
III.
C1
sp
sp2
sp3
sp2
sp3
A.
B.
C.
D.
E.
B. II only
C. III only
D. I and II
E. I and III
-------------------------------------------------------------------------------------10. What is the mass of sulfur that contains 2.45 " 1016 S atoms?
#17
NH2
O
NH2
A. I only
A. 4.08 " 10
-------------------------------------------------------------------------------------11. What hybrid orbitals are used for bonding on the carbons labeled
C1 and C2 in the molecule shown.
g
B. 1.30 " 10#6 g
C. 7.68 " 10#5 g
D. 7.86 " 108 g
E. 7.84 " 1017 g
C2
sp
sp2
sp3
sp3
sp
-------------------------------------------------------------------------------------12. Which of these are incorrect Lewis structures?
F
F
N
H
Cl
F
F
F
I
C
C
H
H
H
H
II
H
C
O
O
C
O
H
H
III
A. I only
B. II only
C. III only
D. I and II
E. I and III
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-------------------------------------------------------------------------------------13. What is the maximum number of electrons in an atom that can
have the following set of quantum numbers?
n=4
l= 3
ml = –2
ms = +1/2
-------------------------------------------------------------------------------------16. Which one of these ions has the smallest radius?
A. Cl#
A. 0
B. S2#
B. 1
C. O2#
C. 2
D. K+
D. 6
E. Na+
E. 10
-------------------------------------------------------------------------------------14. What is the percent sulfur in iron (III) sulfate?
-------------------------------------------------------------------------------------17. What is the electron configuration of Co3+?
A. 1s2 2s2 2p6 3s2 3d7
A. 92.5%
B. 1s2 2s2 2p6 3s2 3p6 4s2 4d7
B. 86.66%
C. 1s2 2s2 2p6 3s2 3p6 4s2 3d7
C. 24.06%
D. 1s2 2s2 2p6 3s2 3p6 4s2 3d4
D. 7.503%
E. 1s2 2s2 2p6 3s2 3p6 3d6
E. 6.080 %
-------------------------------------------------------------------------------------15. Select the arrangement of electromagnetic radiation that starts with
the smallest wavelength and increases to the greatest wavelength.
-------------------------------------------------------------------------------------18. Which of these pairs consists of isoelectronic species?
A. Mn2+ and Ar
A. radio, infrared, ultraviolet, gamma rays
B. Zn2+ and Cu2+
B. radio, ultraviolet, infrared, gamma rays
C. Na+ and K+
C. gamma rays, radio, ultraviolet, infrared
D. Cl– and S
D. gamma rays, infrared, radio, ultraviolet
E. K+ and Cl–
E. gamma rays, ultraviolet, infrared, radio
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-------------------------------------------------------------------------------------19. Which of the following compounds has the highest melting point?
-------------------------------------------------------------------------------------21. What are the electron domain geometry (EDG) and the polarity of
these two molecules?
A. CaO
KrF2
B. MgO
C. BaO
D. BaS
E. NaCl
-------------------------------------------------------------------------------------20. Which one of the following is a structural isomer of cyclohexanol?
SO3
Polar or
nonpolar?
EDG
A.
B.
C.
D.
linear
nonpolar
Trigonal bipyramid
polar
linear
nonpolar
bent
E.
Trigonal bipyramid
Polar or
nonpolar?
EDG
Tetrahedral
Trigonal planar
polar
polar
polar
Trigonal planar
Trigonal planar
nonpolar
Trigonal planar
nonpolar
nonpolar
nonpolar
-------------------------------------------------------------------------------------22. Put these in order of increasing vapor pressure at room
temperature.
O
O
Cl
i
A. I only
B. II only
C. III only
D. I and II
E. I and III
--------------------------------------------------------------------------------------
ii
iii
A. iii < i < ii
B. i = iii < ii
C. i < ii < iii
D. iii < ii < i
E. ii < i < iii
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-------------------------------------------------------------------------------------23. Which one of these correctly depicts a H-bond?
H
A.
H
C
O
H
H
H
B.
H
N
H
H
H
O
C
H
D. H
H
H
H
C
H
H
C
O
H
H
E. H
H
H
H
H
C
N
O
C
H
H
H
H
C
N
H
H
H
"Hf° (kJ/mol)
H
H
H
O
C
-------------------------------------------------------------------------------------25. What is the "Hrxn for the reaction between calcium chloride and
silver nitrate if aqueous solutions containing them are mixed and
two moles of silver chloride are formed? Use the following
standard enthalpies of formation
"Hf° (kJ/mol)
+
AgNO3(s)
#123.0
Ag (aq)
+105.9
Ca(NO3)2(s)
#938.2
Ca2+(aq)
–543.0
AgCl(s)
#127.0
NO3 (aq)
#206.6
CaCl2(s)
#795.4
Cl#(aq)
#167.2
#
H
H
A. #548.4 kJ
B. #283.4 kJ
F
C.
H
C
C. #131.4 kJ
F
F
H
H
C
F
H
-------------------------------------------------------------------------------------24. At what temperature would a mole of 37Cl2 gas have a root mean
square velocity equal to the speed of sound, 331.3 m/s, at 1
atmosphere?
A. 17.6 K
B. 163 K
C. 273 K
D. 326 K
E. 16300 K
--------------------------------------------------------------------------------------
D. #67.4 kJ
E. #38.4 kJ
-------------------------------------------------------------------------------------26. At 375 °C the equilibrium constant for the reaction below is 1.2.
N2(g) + 3H2(g) ! 2NH3(g)
At some time during the reaction, the [N2]=0.036 M, [H2]=4.6"10#3 M,
and [NH3]=9.1"10#4 M. Which of the following is true?
A. Q = K so the reaction is at equilibrium; the concentrations
will not change
B. Q > K so the reaction will produce more product.
C. Q > K so the reaction will produce more reactants.
D. Q < K so the reaction will produce more product.
E. Q < K so the reaction will produce more reactants.
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-------------------------------------------------------------------------------------27. Use bond energies to estimate the enthalpy change for the reaction of
one mole of CH4 with chlorine gas to give CH3Cl and hydrogen
chloride.
CH4 (g)+ Cl2 (g) ! CH3Cl (g)+ HCl(g)
!"#$%
&%'()*+",-%
./0%
.,/.,%
0/.,%
./.,%
121%()*+",%
314%()*+",%
143%()*+",%
435%()*+",%
-------------------------------------------------------------------------------------29. A 350. mL sample of 0.276 M HNO3 is partially neutralized by
125 mL of 0.120 M Ca(OH)2. Find the concentration of nitric acid
in the resulting solution.
A. 0.210 M
B. 0.00632 M
C. 0.203 M
D. 0.0240 M
E. 0.140 M
A. #101 kJ/mol
B. #106 kJ/mol
C. +331 kJ/mol
D. +106 kJ/mol
E. +101 kJ/mol
-------------------------------------------------------------------------------------28. Consider this reaction at equilibrium:
2H2O2(g) !"2H2O(g) + O2(g)
"Hºrxn = –210 kJ/mol
If the volume of the system is expanded at constant temperature,
what change will occur in the position of the equilibrium?
A. It will shift to the left, producing more H2O2
-------------------------------------------------------------------------------------30. Terephthalic acid, used in the production of polyester fibers and
films, is composed of carbon, hydrogen, and oxygen. When 0.6943 g
of terephthalic acid was subjected to combustion analysis it produced
1.471 g CO2 and 0.226 g H2O. What is its empirical formula?
A. C2H3O4
B. C3H4O2
C. C4H3O2
D. C5H12O4
E. C2H2O
B. It will shift to the right, producing more O2
C. No change will occur.
D. It will shift to the left, to use up some H2O
E. The pressure will decrease.
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-------------------------------------------------------------------------------------31. A mixture of 12.2 g of potassium and 22.2 g of bromine (Br2) was
allowed to react. If 30.3g of KBr was collected, what is the percent
yield for this reaction?
2 K(s) + Br2(!) ! 2 KBr(s)
-------------------------------------------------------------------------------------33. One mole of ice in a coffee cup at #10°C absorbs 15.9 kJ of heat.
Which point on the phase diagram below describes the final state
of the system.
C (s) = 2.03 J/g-°C
A. 49.8 %
C (!) = 4.184 J/g-°C
B. 55.1 %
C (g) = 1.84 J/g-°C
C. 61.4 %
"Hfus = 6.01 kJ/mol
D. 81.7 %
E. 91.5 %
-------------------------------------------------------------------------------------32. If a typical car contains 1100 kg of steel, how much energy does it
take to heat the steel for recycling from 20 °C to a liquid at 1500 °C
if the steel melts at 1450 °C?
Cp(s) = 0.49 kJ/kg-°C
Cp(!) = 1.19 kJ/kg-°C
"Hfus = 274.0 kJ/kg
A. 4.358 $105 kJ
B. 7.942 $105 kJ
C. 8.238 $105 kJ
D. 1.135 $106 kJ
E. 2.369 $106 kJ
--------------------------------------------------------------------------------------
E
•
"Hvap = 40.67 kJ/mol
A.
B.
C.
D.
E.
-------------------------------------------------------------------------------------34. What is the hydroxide ion concentration in a solution made by
adding 20.0 g of NaOH to 100 mL of 0.50 M solution of KOH and
diluting it until the final volume of the solution is 0.500L?
A. 0.21 M
B. 0.55M
C. 0.91 M
D. 1.0 M
E. 1.1 M
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-------------------------------------------------------------------------------------35. From the following list of aqueous solutions and water, select the
one with the highest boiling point.
-------------------------------------------------------------------------------------37. What is the osmotic pressure of a solution prepared from 13.7 g of
HCl and enough water to make 0.500 L of solution at 18°C?
A. 1.0 M Li3PO4
A. 0.55 atm
B. 1.0 M NH4NO3
B. 1.10 atm
C. 0.75 M CuCl2
C. 8.95 atm
D. 2.0 M glucose
D. 19.7 atm
E. pure water
E. 35.9 atm
-------------------------------------------------------------------------------------36. Ammonium iodide dissociates reversibly to ammonia and
hydrogen iodide.
NH4I(s) ! NH3(g) + HI(g)
At 400°C, Kp = 0.215. Calculate the partial pressure of ammonia at
equilibrium when a sufficient quantity of ammonium iodide is heated
to 400°C.
A. 0.103 atm
B. 0.215 atm
C. 0.232 atm
D. 0.464 atm
E. 2.00 atm
-------------------------------------------------------------------------------------38. A photon (h%) is needed to cause the dissociation of N2 in the
upper atmosphere.
N
N
+ h$ ! 2 N
N bond energy is 941 kJ per mole. What is the maximum
The N
wavelength of light needed to cause the dissociation of N2?
A. 80.2 nm
B. 127 nm
C. 325 nm
D. 640 nm
E. 941 nm
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-------------------------------------------------------------------------------------39. A gaseous compound is 30.4% nitrogen and 69.6% oxygen by
mass. A 5.25-g sample of the gas occupies a volume of 1.00 L and
exerts a pressure of 1.26 atm at –4.0°C. What is the molecular
formula of the compound?
A. NO
B. NO2
C. N2O4
D. N2O5
E. N3O6
-------------------------------------------------------------------------------------40. Which of these will have delocalized %-bonding?
O
O
H3 C
C
OH
I.
O
N
II.
O
O
O
O
III.
A. I only
B. II only
C. I and III
D. I and II
E. II and III
---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------END OF EXAM
CHEMISTRY 110 FINAL EXAM
May 3, 2013
Answer Key
FORM A
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
41.
C
C
E
D
C
C
D
E
C
B
D
D
B
C
E
E
E
E
B
C
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
E
A
E
D
C
C
A
B
E
C
E
D
C
E
A
D
E
B
C
E