SOLUTION
Final Exam Preparation problems for Chemistry 11
1. A dilute HCl solution is to be prepared from a more concentrated solution. Which of pieces of glassware will give the
highest level of precision?
(A) graduated cylinder and volumetric flask
(C) pipette and graduated cylinder
(B) two graduated cylinders
(D) pipette and volumetric flask
2. An alloy of gold and silver contains 38.5% silver by mass and has a density of 14.6 g mL¯ 1. What is the molar
concentration of silver in this alloy?
(A) 52.1 mol L¯1
(B) 45.6 mol L¯1
(C) 3.57 mol L¯1
(D) 2.64 mol L¯1
3. As2S3 reacts with O2 to give SO2 and As2O3. What is the smallest whole number coefficient for O2 when the equation
for this reaction is balanced correctly?
_As2S3(s) + _O2(g) ---> _As2O3(s) + _SO2(g)
(A) 3
(B) 5
(C) 7
(D) 9
4. A 0.242 g sample of potassium is heated in oxygen. The result is 0.440 g of a crystalline compound. What is the
formula of this compound?
(A) KO
(B) K2O
(C) KO2
(D) KO3
5. What volume of 3.0 M Na2SO4 must be added to 25 mL of 1.0 M BaCl2 to produce 5.0 g of BaSO4?
(A) 7.2 mL
(B) 8.3 mL
(C) 10.0 mL
(D) 14 mL
6. These three equations describe an oxidation-reduction method for determining dissolved oxygen in water. How
many moles of S2O32¯ are equivalent of each mole of O2?
1) 2Mn2+(aq) + 4OH¯(aq) + O2(g) ---> 2MnO2(s) + 2H2O(l)
2) MnO2(s) + 2I¯(aq) + 4H+(aq) ---> Mn2+(aq) + I2(aq) + 2H2O(l)
3) 2S2O32¯(aq) + I2(aq) ---> S4O62¯(aq) + 2I¯(aq)
(A) 0.5
(B) 1
(C) 2
(D) 4
7. A 15 mL sample of 0.20 M MgCl2 is added to 45 mL of 0.40 M AlCl3. What is the molarity of Cl¯ ions in the final
solution?
(A) 1.0 M
(B) 0.60 M
(C) 0.35
(D) 0.30 M
8. How many electrons are present in 2.0 x 10¯3 moles of 188O2¯?
(A) 1.2 x 1021
(B) 9.6 x 1021
(C) 1.2 x 1022
(D) 1.9 x 1022
9. In which change of state are covalent bonds broken?
(A) evaporation of water
(C) vaporization of diamond
(B) fusion of sodium chloride
(D) sublimation of dry ice
10. By what factor does the average velocity of a gaseous molecule increase when the absolute temperature is
doubled?
(A) 1.4
B) 2.0
(C) 2.8
(D) 4.0
11. Which species is expected to have the highest boiling point at 1 am pressure?
(A) O2
(B) CO
(C) CO2
(D) HCHO
12.
Calculate H° for this reaction.
C2H2(g) + 2H2(g) ---> C2H6(g)
Combustion, kJ mol¯1
(A) -312 kJ
C2H2(g)
-1300
H2(g)
-286
C2H6(g)
-1560
(B) -26 kJ
(C) +26 kJ
(D) +312 kJ
13. Which statement about work and heat is true?
(A) A given quantity of heat can be completely converted to work.
(B) Heat and work are both state functions.
(C) Some heat is always produced when work is done.
14. How many moles of elections are transferred when this equation is balanced with the smallest whole number
coefficients?
_IO3¯ + _H2O2 + _H+ ---> _I2 + _O2 + _H2O
(A) 2
(B) 4
(C) 5
(D) 10
15. The visible spectrum of the hydrogen atom consists of a series of lines that
A. converge at low energies.
C. are separated by equal energies.
B. converge at high energies.
D. are randomly spaced.
16. When the elements C, N and Si are arranged in order of increasing first ionization energy, which is the correct
order?
A. C < N < Si
B. N < C < Si
C. Si < C < N
D. Si < N < C
17. Which is a possible set of quantum numbers for a valence electron in ground state atom of phosphorus?
A.
B.
C.
D.
n
2
3
3
3
l
1
0
1
2
ml
0
0
-1
1
ms
+1/2
0
+1/2
-1/2
18. These are the first eight ionization energies for a particular neutral atom. All values are expressed in MJ mol¯ 1.
How many valence electrons does this atom possess?
A. 1
1st
2nd
3rd
4th
1.31
3.39
5.30
7.47 10.99 13.33 71.33 84.01
B. 2
5th
6th
C. 4
7th
8th
D. 6
19. Which gaseous ion in its ground state has the greatest number of unpaired electrons?
A. Mn3+
B. Fe3+
C. Co3+
D. Ni3+
20. Which of these characteristics describe the PCl3 molecule?
I trigonal planar shape
A. I and II only
II sp3 hybridized phosphorus atom
B. II and III only
C. I and IV only
III polar bonds IV nonpolar molecule
D. I, III, and IV only
21. According to the Lewis structure for the HNNH, how many sigma bonds, pi bonds, and lone pairs of electrons are
present?
A.
B.
C.
D.
sigma bonds pi bonds lone pairs of electrons
2
2
2
3
2
0
3
1
2
3
0
4
22. In the Lewis structure for the BrF4¯ ion, how many lone pairs of electrons are placed around the central atom?
(A) 0
(B) 1
(C) 2
(D) 3
23. What term is used for the measure of an atom's attraction for the electrons that constitute a covalent bond?
(A) ionization energy
(B) bond energy
(C) electron affinity
(D) electronegativity
24. One way of writing the Lewis structure of the cyanate ion, OCN¯, places one double bond between the carbon
atom and the oxygen atom and another double bond between the carbon atom and the nitrogen atom. What are the
formal charges on the oxygen, carbon, and nitrogen atoms, respectively for this structure?
(A) 0, 0, -1
(B) -1, 0, 0
(C) -1, +1, -1
(C) -2, 1, 0
25. All of these species have the same number of valence electrons as NO3¯ except
(A) CO32¯
(B) HCO3¯
(C) NF3
(D) SO3
(C) BF3, AlF3, TlF3
(D) I2, CaO, CH3Cl
26. Which set contains no ionic species?
(A) NH4Cl, OF2, H2S
(B) CO2, Cl2, CCl4
27. Which element exhibits both +1 and +3 oxidation numbers in its compounds?
(A) B
(B) Be
(C) Sn
(D) Ti
28. Which are nonpolar molecules?
1. NCl3
(A) 1 only
2. SO3
3. PCl5
(B) 2 only
(C) 1 and 3 only
(D) 2 and 3 only
29. When FeCl3 is ignited in an atmosphere of pure oxygen, this reaction takes place.
4 FeCl3(s) + 3 O2 (g) ---> 2 Fe2O3(s) + 6 Cl2 (g)
If 3.0 mol of FeCl3 are ignited in the presence of 2.0 mol of O2 gas, how much of which reagent is present in excess
and therefore remains unreacted?
(A) 0.33 mol FeCl3 remain unreacted
(C) 0.25 mol O2 remain unreacted
(B) 0.67 mol FeCl3 remain unreacted
(D) 0.50 mol O2 remain unreacted
30. How many grams of SbF3 are needed to produce a gram of Freon-12, CCl2F2, according to the reaction
represented by this equation?
3 CCl4 + 2 SbF3 ---> 3 CCl2F2+ 2 SbCl3
Substance Molar Mass
(A) 0.667g
(B) 0.986g
SbF3
179 g mol¯1
CCl2F2
121 g mol¯1
(C) 1.50g
(D) 2.22g
31. A self-contained breathing apparatus uses potassium superoxide, KO 2, to convert the carbon dioxide and water in
exhaled air into oxygen, as shown by the equation.
4 KO2(s) + 2 H2O (g) + 4 CO2(s) ---> 4 KHCO3(s) + 3 O2 (g)
How many molecules of oxygen gas will be produced from the 0.0468 g of carbon dioxide that is exhaled in a typical
breath?
(A) 4.8 x 1020
(B) 6.4 x 1020
(C) 8.5 x 1020
(D) 1.9 x 1021
32. A student finds that 31.26 mL of a 0.165 M solution of barium hydroxide, Ba (OH) 2, solution is required to just
neutralize 25.00 mL of a citric acid, H 3C6H5O7, solution. What is the concentration of the H3C6H5O7 solution?
(A) 0.413 M
(B) 0.309 M
(C) 0.206 M
(D) 0.138 M
33. Which Group III element is expected to have physical and chemical properties that are the least similar to the other
elements in that family?
(A) B
(B) Al
(C) Ga
(D) Tl
34. A pure gas that is 14.4% hydrogen and 85.6% carbon by mass has a density of 2.5 g L¯1 at 0 °C and 1 atm
pressure. What is the molecular formula of the gas?
(A) CH2
(B) C2H4
(C) C4H8
(D) C6H12
35. Sodium chloride, NaCl, usually crystallizes in a face-centered cubic lattice. How many Cl¯ ions are in contact with
any single Na+ ion?
(A) 4
(B) 6
(C) 8
(D) 12
36. Use the bond energies in the table to determine H for the formation of hydrazine, N2H4, from nitrogen and
hydrogen according to this equation:
N2(g) + 2 H2(g) ---> N2H4(g)
Bond Energies
N-N
159 kJ mol¯1
N=N
418 kJ mol¯1
N {triple bond} N 941 kJ mol¯1
(A) H = 711 kJ
H-H
436 kJ mol¯1
H-N
389 kJ mol¯1
(B) H = - 98 kJ
(C) H = + 98 kJ
(D) H = + 711 kJ
37. Use the given heats of formation to calculate the enthalpy change for this reaction:
B2O3(s) + 3 COCl2(g) ---> 2 BCl3(g) + 3 CO2(g)
Enthalpy of Formation Data, kJ mol¯1
(A) 694.3 kJ
B2O3(s)
- 1272.8
COCl2(g)
- 218.8
BCl3(g)
- 403.8
CO2(g)
- 393.5
(B) 354.9 kJ
(C) -58.9 kJ
(D) -3917.3 kJ
38. What is the change in internal energy, E, for a system that does 70 joules of work as it absorbs 45 joules of heat?
(A) 115 J
(B) 25 J
(C) -25 J
(D) -115 J
39. When this oxidation-reduction equation is correctly balanced, what is the mole ratio of reducing agent to oxidizing
agent?
MnO4¯ + Sn2+ + H+ ---> Mn2+ + Sn4+ + H2O
(A) 1:1
(B) 2:1
(C) 4:1
40. The hydrogen line spectrum provides evidence for the
(D) 5:2
(A) Heisenberg Uncertainly Principle
(C) diatomic nature of H2
(B) wavelike properties of light
(D) quantized nature of atomic energy states
41. What is the number of unpaired electrons in a manganese atom (Z = 25) in its lowest energy states?
(A) 1
(B) 3
(C) 5
(D) 7
42. Ions with the electronic structure 1s2 2s2 2p6 3s2 3p6 would not be present in which aqueous solution?
(A) NaF(aq)
(B) NaCl(aq)
(C) KBr(aq)
(D) CaI2(aq)
43. An element with the electron configuration [Xe]4f14 5d7 6s2, is
(A) an alkaline earth element
(B) a transition element
(C) an inert gas
(D) a rare earth
44. The bonds in ozone, O3, are best represented as
(A) two double bonds
(C) distinct single and double bonds
(B) a single and a double bond that switch positions rapidly
(D) something between a single and a double bond
45. Which pair of substances will have the most similar geometry?
(A) SO3 and SO32¯
(B) SO3 and CO32¯
(C) SO3 and SO42¯
(D) SO42¯ and CO32¯
(C) dsp3
(D) d2sp3
46. What hybridization is expected for ClF3?
(A) sp3
(B) dsp2
47. Which bond properties are consistent with one another?
Bond Order Bond Length
(A)
higher
shorter
(B)
higher
longer
(C)
lower
shorter
48. Which hydrogen halide would you expect to have the lowest boiling point?
(A) HF
(B) HCl
(C) HBr
(D) HI
(C) C2Cl2
(D) C2Cl4
49. Which substance has a dipole moment?
(A) CCl4
(B) CH2Cl2
50. When the isoelectronic species, K+, Ca2+, and Cl¯, are arranged in order of increasing radius, what is the correct
order?
(A) K+, Ca2+, Cl¯
(B) K+, Cl¯, Ca2+
(C) Cl¯, Ca2+, K+
(D) Ca2+, K+, Cl¯
51. Which Group 2 element has chemical properties least like the other members of the group?
(A) Be
(B) Ca
(C) Sr
(D) Ba
52. In the vapor state which atom has the largest ionization energy?
(A) Na
(B) K
(C) Mg
(D) Ca
53. When equal volumes of 1 M Na2SO4 and 1 M solutions of two different ions are mixed, a precipitate forms with one
of the ions but not with the other. The two ions could be
(A) Ba2+ and Mg2+
(B) Al3+ and Zn2+
(C) Cu2+ and K+
(D) Pb2+ and Ba2+
54. The geometry of the atoms in the species PCl4+ is best described as
(A) tetrahedral
(B) see-saw
(C) square planar
(D) trigonal bipyramidal
55. When 4.50 g of Fe2O3 is reduced with excess H2 in a furnace, 2.60 g of metallic iron is recovered. What is the
percent yield? The Molar Mass of Fe2O3 is 159.7 g mol¯1
Fe2O3 + 3 H2 ---> 2 Fe + 3 H2O
(A) 82.6
(B) 70.0
(C) 57.8
(D) 31.5
56. Which of these compounds contains the greatest percentage of nitrogen?
(A) C6H3N3O7
(B) CH4N2O
(C) LiNH2
(D) Pb(N3)2
57. Analysis shows a certain compound to be 37.51% C, 4.17% H, and 58.32% O. What is its empirical formula?
(A) C3H4O4
(B) C4H5O5
(C) C5H7O6
(D) C6H8O7
58. A sample of a compound of xenon and fluorine contains molecules of a single type; XeF n, where n is a whole
number. If 9.03 x 1020 of these XeFn molecules have a mass of 0.311 g, what is the value of n?
(A) 2
(B) 3
(C) 4
(D) 6
59. The combustion reaction of C3H8O in O2 is represented by this equation.
2 C3H8O + 9 O2 ---> 6 CO2 + 8 H2O
When 3.00 g C3H8O and 7.38 g O2 are combined, how many moles of which reagent remain?
(A) 0.0056 mol O2
(B) 0.024 mol C3H8O
(C) 0.24 mol O2
(D) 0.18 mol C3H8O
60. Formaldehyde is oxidized by dichromate ions in acid solution to give formic acid as represented by this equation.
3 HCOH + Cr2O72¯ + 8 H+ ---> 3 HCOOH + 2 Cr3+ + 4 H2O
If 15.62 mL of 0.125 M K2Cr2O7 exactly react with 25.00 mL of formaldehyde solution, what is the molarity of the
formaldehyde?
(A) 0.00585 M
(B) 0.0260 M
(C) 0.0781 M
(D) 0.234 M
61. If 0.25 mol of a gas has a mass of 4.0 g and occupies a volume of 5.6 L at standard temperature and pressure,
what would be the mass and volume of 0.50 mol of this gas at standard temperature and 2.0 atm pressure?
(A) 4.0 g and 5.6 L
(B) 4.0 g and 11 L
(C) 8.0 g and 5.6 L
(D) 8.0 g and 11 L
62. If 34.0 mL of O2 are collected over H2O at 740 mmHg and 25 °C, what will be the volume of dry O2 at 0 °C and 760
mmHg? Vapor Pressure at 25 °C of H2O is 23.8 mmHg
(A) 29.4 mL
(B) 30.3 mL
(C) 32.0 mL
(D) 33.1 mL
63. What is the molar mass of an ideal gas if a 0.622 g sample of this gas occupies a volume of 300. mL at 35 °C and
789 mmHg?
(A) 44.8 g mol¯1
(B) 48.9 g mol¯1
(C) 50.5 g mol¯1
(D) 54.4 g mol¯1
64. Which is true about equal volumes of CH4 and O2 at 20 °C and 1 atm pressure?
(A) The CH4 sample has a mass that is one-half that of the O2 sample.
(B) The number of O2 molecules is twice as large as the number of CH4 molecules.
(C) The average kinetic energy of the O2 molecules is one-half that of the CH4 molecules.
(D) The average velocity of the O2 molecules is one-half that of the CH4 molecules.
65. 168.00 J of energy are added to a sample of gallium initially at 25.0 °C, the temperature rises to 38.0 °C. What is
the volume of the sample?
Data for Gallium, Ga
specific heat 0.372 J g¯1 °C¯1
density
(A) 2.38 cm3
5.904 g cm¯3
(B) 4.28 cm3
(C) 5.88 cm3
(D) 31.0 cm3
66. The combustion of ammonia is represented by this equation.
4 NH3(g) + 5 O2(g) ---> 4 NO(g) + 6 H2O (g)
H=- 905 kJ
Enthalpy of formation data
NO2(g)
90.4 kJ mol¯1
H2O(g)
- 241 kJ mol¯1
What is the enthalpy of formation for NH3(g)?
(A) - 499 kJ mol¯1
(B) - 46.1 kJ mol¯1
(C) 184 kJ mol¯1
(D) -44.9 kJ mol¯1
67. Which electronic transition occurs with the greatest release of energy in a hydrogen atom?
(A) n = 2 --> n = 3
(B) n = 3 --> n = 9
(C) n = 9 --> n = 3
(D) n = 3 --> n = 2
68. For which element could the last electron have the quantum numbers n = 4, l = 2?
(A) Ca (Z = 20)
(B) Ti (Z = 22)
(C) Si (Z = 14)
(D) Rh (Z = 45)
69. Which atom in its ground state contains the greatest number of unpaired electrons ?
(A) S (Z = 16)
(B) P (Z = 15)
(C) Si (Z = 14)
(D) Al (Z = 13)
70. Which of these isoelectronic species will be the largest?
(A) S2¯
(C) K+
(B) Cl¯
(D) Ca2+
71. Which process will release the greatest quantity of energy?
(A) O(g) ---> O+(g) + e¯
(C) O¯(g) + e¯ ---> O2¯(g)
(B) O+(g) ---> O2+(g) + e¯
(D) O(g) + e¯ ---> O¯(g)
72. What are the hybridizations of carbon 1 and carbon 2 in the hydrocarbon? (Carbon 1 is the carbon farthest to the
left and carbon 2 is the one boldfaced, the middle of the three carbons.)
CH3CH=CH2
3
3
(A) sp , sp
(B) sp , sp
2
(C) sp2, sp2
(D) sp, sp2
73. According to valence bond theory, what hybrid orbital are used by the central atom in SF4?
(A) sp3
(B) dsp2
(C) dsp3
(D) d2sp3
74. What is the maximum number of covalent bonds that can be formed by an element with the outer electron
configuration of 3s2 3p4?
(A) 2
(B) 3
(C) 4
(D) 6
75. In which pair of species do the central atoms have the same geometry?
(A) NH3, NO3¯
(B) BF3, NO3¯
C) BF3, ClF3
(D) NH3, ClF3
76. Use the given bond energies and this equation to calculate the H-F bond energy in kJ mol¯1
Bond Energies, kJ mol¯1
H2
436
F2
135
H2(g) + F2(g) ---> 2 HF (g) H = - 541 kJ
(A) 1130
(B) 556
(C) 48
(D) 24
77. Which element can exhibit more than one oxidation state in compounds?
1. Cr
2. Pb
(B) 1 and 2 only
(A) 1 only
3. Sr
(C) 2 and 3 only
(D) 1,2 and 3
78. When these species are arranged in order of increasing bond energy, what is the correct sequence?
(A) N2, O2, F2
(B) F2, O2, N2
(C) O2, F2, N2
79. All of these sets of quantum numbers are permissible except
n
l
ml
ms
(D) O2, N2, F2
(A)
(B)
(C)
(D)
1
2
3
3
0
2
1
2
0
0
1
-1
+1/2
-1/2
-1/2
+1/2
80. A 20.00 mL sample of a Ba(OH)2 solution is titrated with 0.245 M HCl. If 27.15 mL of HCl is required, what is the
molarity of the Ba(OH)2 solution?
(A) 0.166 M
(B) 0.180 M
(C) 0.333 M
(D) 0.666 M
81. 0.250 g of an element, M, reacts with excess fluorine to produce 0.547 g of the hexafluoride, MF 6. What is the
element?
(A) Cr
(B) Mo
(C) S
(D) Te
82. How many moles of Na+ ions are in 20 mL of 0.40 M Na3PO4?
(A) 0.0080
(B) 0.024
(C) 0.050
(D) 0.20
83. What is the mass percent of oxygen in Al2(SO4)3 . 18 H2O (The molar mass of this substance is 666.43 g / mol)?
(A) 9.60
(B) 28.8
(C) 43.2
(D) 72.0
84. What is the coefficient for H+(aq) when the equation is balanced with whole number coefficients?
_Mn2+(aq) + _BiO3¯(aq) + _H+(aq) <===> _Bi3+(aq) + _MnO4¯(aq) + _H2O (l)
(A) 3
(B) 4
(C) 7
(D) 14
85. What is the number of O2 molecules in the 2.5 g of O2 inhaled by the average person in one minute?
(A) 1.9 x 1022
(B) 3.8 x 1022
(C) 4.7 x 1022
(D) 9.4 x 1022
86. The molar mass of a gas with a density of 5.8 g L¯1 at 25 °C and 740 mmHg is closest to
(A) 10 g mol¯1
(B) 20 g mol¯1
(C) 150 g mol¯1
(D) 190 g mol¯1
87. Which substance would be expected to exhibit the greatest surface tension at 25 °C?
(A) CH3OCH3
(B) C2H5OH
(C) CH3CH(OH)CH3
(D) CH2(OH)CH2OH
88. What is the H°f for N2O in kJ mol¯1 (heats of formation: NH3 = -45.9 kJ mol¯1 and H2O = -241.8 kJ mol¯1) ?
3 N2O(g) + 2 NH3(g) ---> 4 N2(g) + 3 H2O(g)
(A) +246
(B) +82
H = -879.6 kJ
(C) –82
(D) -246
89. What is the change in internal energy, E, for a reaction that gives off 65 joules of heat and does 38 joules of
work?
(A) -103 J
(B) -27 J
(C) +27J
(D) +103 J
90. The value of H for a reaction can be found by appropriate combination of bond enthalpies (the energy required to
break a particular bond, represented BE). Which expression will give H for this reaction?
C2H4(g) + H2(g) ---> C2H6(g)
(A) BEC=C +BEH-H - [BEC-C + 2BEC-H]
(C) (1/2)BEC=C + BEH-H - 2BEC-H
(B) BEC-C + 2BEC-H - [BEC=C + BEH-H]
(D) 2BEC-H - (1/2)BEC=C + BEH-H