Final Exam Practice
1. Three students measured an amount of water using a burette. The actual amount of water each
student measured was 15.00 mL. The following is their results.
Nancy
Tucker
Zelda
Trial 1
13.27mL
11.11mL
14.25mL
Trial 2
22.22mL
11.09mL
14.95mL
Trial 3
17.88mL
11.10mL
15.75mL
The most precise student was ________. The student with systematic error was ________.
A) Tucker, Tucker
B) Zelda, Nancy
C) Tucker, Zelda
D) Nancy, Tucker
E) Zelda, Tucker
2. You ordered a package online and noticed on the website that it was being shipped in a box
that had a volume of 3.75 m3. What is the volume of the box in ft3?
(2.54 cm = 1.00 in.; 12.0 in. = 1.00 ft)
A) 1.35 ft3
B) 173 ft3
C) 114 ft3
D) 132 ft3
E) 1.23x10-3 ft3
3. What is the formula of a compound when calcium (Ca) and nitrogen (N) come together?
A) CaN
B) Ca2N3
C) Ca3N2
D) Ca2N2
E) Ca3N3
4. What would the formula for triphosphorus pentabromide?
A) PBr
B) P2Br6
C) P3Br7
D) P3Br4
E) P3Br5
5. 16. What is the name of Cr(NO3)3?
A) chromium(III) nitrate
B) chromium(I) nitrate
C) chromium trinitride
D) chromium(II) nitrate
E) chromium nitride
6. A compound is found to be made up of 50.0% C, 11.1% H, and 38.9% N by mass. What is the
compound’s empirical formula? (C = 12.0 g/mole; H = 1.0 g/mole; N = 14.0 g/mole)
A) CHN
B) C5HN4
C) C2H4N
D) C4H11N3
E) C3H8N2
4+
7. #"
!"𝐺𝑒 has _________ electrons and _________ neutrons.
A) 31 electrons, 71 neutrons
B) 35 electrons, 40 neutrons
C) 75 electrons, 31 neutrons
D) 27 electrons, 40 neutrons
E) 67 electrons, 102 neutrons
8. How many moles of NOBr (molar mass = 109.92 g/mole) are in a 645g sample of NOBr?
A) 535 mole NOBr
B) 0.170 mole NOBr
C) 5.87 mole NOBr
D) 755 mole NOBr
E) 7.09x104 mole NOBr
9. How many grams of K3PO4 (molar mass = 212 g/mole) are in a sample that contains 7.45x1023 oxygen
atoms?
A) 65.6g K3PO4
B) 262g K3PO4
C) 16.4g K3PO4
D) 197g K3PO4
E) 1.24g K3PO4
10. How many total moles of Na+ ions are in an aqueous solution that has 0.50 moles of Na2S dissolved in
water?
A) 0.5 total moles of ions
B) 1.0 total moles of ions
C) 3.0 total moles of ions
D) 1.5 total moles of ions
E) 0.25 total moles of ions
11. Calculate the average atomic mass of the pretend element Cincinnatium (Uc) using the following
data:
Isotope % abundance
mass
71
Uc
67.45%
71.055 amu
73
Uc
12.25%
73.029 amu
75
Uc
20.30%
75.100 amu
A) 74.34 amu
B) 72.89 amu
C) 72.12 amu
D) 71.68 amu
E) 73.06 amu
(0.6745)(71.055) + (0.1225)(73.029) + (0.2030)( 75.100) = 72.12 amu
12. Consider the following balanced chemical equation: 4 Ag + O2 à 2 Ag2O
How many grams of Ag2O (232 g/mole) can be produced from 135g Ag (108 g/mole) and excess O2?
A) 580.g Ag2O
B) 31.4g Ag2O
C) 67.5g Ag2O
D) 92.8g Ag2O
E) 145g Ag2O
13. Balance the following equation. When balanced, what is the coefficient in front of SO2?
A) 8
B) 4
C) 2
D) 11
E) 5
____ FeS2 + ____ O2 à ____ SO2 + ____ Fe2O
14. Consider the following balanced chemical equation: 2 C2H2 + 5 O2 à 4 CO2 + 2 H2O
What is the limiting reactant if 235g C2H2 (26.0 g/mole) is reacted with 288g O2 (32.0 g/mole)?
A) all compounds listed are limiting
B) no compounds listed are limiting
C) O2
D) C2H2
E) CO2
15. Consider the following balanced chemical equation: 2 Al + 3 CuSO4 à Al2(SO4)3 + 3 Cu
How much excess reactant do you have left if you reacted 75.0g Al (26.98 g/mole) with 95.0g CuSO4
(159.6 g/mole)?
A) 64.3g excess reactant
B) 10.7g excess reactant
C) 84.3g excess reactant
D) 4.17g excess reactant
E) 0.595g excess reactant
16. In a chemical reaction Carla the chemist set up a chemical reaction in the lab to make
caffeine. She calculated that she could theoretically make 25.45 grams of caffeine. In the lab she
actually ended up making 18.32 grams of caffeine. What was her % yield?
A) 71.98 %
B) 1.389 %
C) 28.02 %
D) 7.13 %
E) 43.77 %
17. The following scene represents the chemical reaction between AB2 and B2 to form AB3 in the
following reaction: 2AB2 + B2 → 2AB3
What is the limiting reactant?
A. AB2
B. B2
C. Stoichiometric amounts, no limiting reactant
18. How many grams of K3PO4 (212 g/mole) need to be dissolved in water to make 525 mL of a 0.999M
K3PO4 solution?
A) 111g
B) 2.47g
C) 524g
D) 313g
E) 737g
!#
525 mL × !$$$ %# ×
$.''' %() *! +,"
!#
-!- . * +,
× ! %() *! +," = 111 g K / PO0
!
"
19. 5. Consider: 3 Ba(OH)2(aq) + Fe2(SO4)3(aq) à 3 BaSO4(s) + 2 Fe(OH)3(s)
What is the theoretical yield in grams of Fe(OH)3 (107 g/mole) if 815 mL of a 1.45M solution of Ba(OH)2is
reacted with excess Fe2(SO4)3?
A) 126g
B) 253g
C) 262g
D) 84.3g
E) 67.8g
!#
815 mL × !$$$ %# ×
!.01 %() 23(,5)#
!#
- %() 78(,5)
!$9 :
× / %() 23(,5)! × ! %() 78(,5) = 84.3 g Fe(OH)/
#
!
20. What are the major ionic species present in solution when Mg(ClO4)2 is dissolved in water?
A) only O2- ions
B) Mg2+ and ClO4- ions
C) Mg2+, Cl-, and O2- ions
D) only Mg2+ ions
E) OMg ions
21. Nitrogen Monoxide reacts with Oxygen to form nitrogen dioxide. The first scene represents a
mixture of reactants. If the reaction has a 66% yield, which scene (A, B, or C) best represents the final
product mixture? Choice B
22. Consider: 2 KOH(aq) + H2SO4(aq) à K2SO4(aq) + 2 H2O(l)
What is the molarity of the KOH solution if it takes 135 mL of the KOH solution to neutralize 187 mL of
an 1.85M H2SO4?
A) 5.13M
B) 1.75M
C) 3.64M
D) 2.56M
E) 1.28M
!#
187 mL × !$$$ %# ×
!.;1 %() 5# <,"
!#
- %() *,5
!
× ! %() 5 <, × !/1 %# ×
#
"
!$$$ =>
!>
= 5.13 M KOH
23. Which of the following is considered the strongest electrolyte?
A) SO2
B) NaOH (strong base – ionic compounds and strong acids and bases are strongest electrolytes)
C) HF
D) C6H12O6
E) NH3
24. What precipitate would be formed in the reaction of AgNO3(aq) + (NH4)3PO4(aq) à
A) no precipitate formed
B) NH4NO3
C) AgNH3
D) NPO7
E) Ag3PO4
25. What are the spectator ions in following reaction:
2 NaBr(aq) + Hg2(NO3)2(aq) à Hg2Br2(s) + 2 NaNO3(aq)
A) Na+ and NO3B) Na+ and BrC) NO3- and BrD) Hg22+and BrE) there are no spectator ions
26. What is the net ionic equation when the following two reactants react: PbBr2(aq) + Na2SO4(aq) à
A) Pb2+(aq) + SO42-(aq) à PbSO4(s)
B) Na+(aq) + Br-(aq) à NaBr(aq)
C) Pb2+(aq) + SO42-(aq) + 2 Na+(aq) + 2 Br-(aq) à Pb2+(aq) + 2 Na+(aq) + 2 Br-(aq) + SO42-(aq)
D) H+(aq) + OH-(aq) à H2O(l)
E) Pb2+(aq) + 2 Na+(aq) à Na2Pb(s)
27. The oxidation number of the element Cd in CdBr42- is
A) -2
B) +6
C) +4
D) +2
E) +1
28. Forming new bonds __________ energy. This is a(n) __________ process.
A) releases, exothermic
B) releases, endothermic
C) absorbs, exothermic
D) absorbs, endothermic
E) does not change, neutral
29. Consider a system which releases 325J of heat to the surroundings and the surroundings does 250.J
of work on the system. What is the DE of the system?
A) -75.0J
B) +75.0J
C) -575J
D) +575J
E) 0J
∆𝐸 = 𝑞 + 𝑤
∆𝐸 = −325 J + 250. J = −75 J
30. A 295g piece of hot unknown metal (unknown specific heat) is placed in 350g of water (c = 4.18
J/g×K). The hot metal had an initial temperature of 455K and the water had an initial temperature of
275K. Assuming no heat loss, if the final temperature of the metal and water together became 287K,
what is the specific heat (c) of the unknown metal?
A) 0.176 J/g×K
B) 2.82 J/g×K
C) 0.354 J/g×K
𝑞 = 𝑐𝑚∆𝑇
C
F!911G H
H
𝑐=?@AB = =∆E = (-'1 .)(-;9*F011*) = 0.354 .∙*
D) 0.252 J/g×K
E) 1.84 J/g×K
31. Which is true of the reaction in cold packs (the cold pack feels cold), when NH4NO3 dissolves in
water?
A. DH < 0, exothermic
B. DH > 0, exothermic
C. DH < 0, endothermic
D. DH > 0, endothermic
E. DH = 0, since cold packs are sealed
The reaction (the system where NH4NO3 dissolves in water) is endothermic because heat is absorbed
from the surroundings – so the surroundings (our hands) feel cold. Endothermic reactions have a +DH.
32. What is the enthalpy change for the following target reaction (ΔHrxn) using Hess’s Law.
Target: C3H8(g) + 5 O2(g) à 3 CO2(g) + 4 H2O(g)
Given:
1. 3 C(s) + 4 H2(g) à C3H8(g)
2. C(s) + O2(g) à CO2(g)
3. H2(g) + ½ O2(g) à H2O(g)
ΔHrxn = -103.8 kJ
ΔHrxn = -393.5 kJ
ΔHrxn = -241.8 kJ
A) -2044 kJ
B) -739.1kJ
C) 255.5 kJ
D) -401.5 kJ
E) -1734 kJ
1. x-1
2. x3
3. x4
33. How many grams of H2O (18.0 g/mole) are formed if 675 kJ of energy is released according to the
following thermochemical equation:
4 NH3 + 5 O2 à 4 NO + 6 H2O
A) 13.9g
B) 55.6g
C) 83.4g
D) 111g
E) 199g
DHrxn = -874 kJ
G %() 5 ,
!;.$ .
−675 kJ × F;90 JK# × ! %() 5 , = 83.3 g H- O
#
34. By definition, which equation shows the enthalpy of formation for C2H6O(l)?
A) 2 C(graphite) + 3 H2(g) + 1/2 O2(g) à C2H6O(l)
B) 4 C(graphite) + 12 H(g) + 2 O(g) à 2 C2H6O(l)
C) 2 C(graphite) + H2O(l) + 4 H+(aq) à C2H6O(l)
35. Consider the balanced equation: 2 NH3(g) + CO2(g) à CO(NH2)2(s) + H2O(l)
Given the following DHf values:
DHf for NH3(g) = -45.9 kJ/mole
DHf for CO2(g) = -393.5 kJ/mole
DHf for CO(NH2)2(s) = -333.5 kJ/mole
DHf for H2O(l) = -285.8 kJ/mole
What is the enthalpy of the reaction (ΔHrxn) above?
A) -230. kJ
B) 605 kJ
C) -1104 kJ
D) -395 kJ
E) -134 kJ
ΔHrxn = [(1x-333.5)+(1x-285.8)] – [(2x-45.9)+(1x-393.5)] = -134 kJ
36. Given the bond energies (BE) below, what is the enthalpy change (ΔHrxn) for the following reaction:
H
N
N
3 H
H
2
H
•
•
•
N
H
BE(N≡N) = 941 kJ
BE(H-H) = 432 kJ
BE(N-H) = 391 kJ
A) 118 kJ
B) -109 kJ
C) -982 kJ
D) 427 kJ
E) -1760 kJ
Bonds broken (+)
1 N≡N
3 H-H
Bonds formed (-)
6 N-H
Add it all together.
37. A radio wave has a frequency of 8.6´108 1/s. What is the energy of one photon of this radiation?
A. 7.7´10-43 J
B. 2.3´10-34 J
C. 5.7´10-25 J
D. 1.7´10-16 J
E. > 10-15 J
E = hn= hc/l
38. What is the wavelength of an x-ray with a frequency of 3.22´1016 s-1?
A.
B.
C.
D.
E.
c = ln
9.32 nm
1.07 nm
10.7 nm
3.22 ´107 nm
932 nm
39. In the Bohr H atom, the __?__ transition results in the emission of the highest-energy photon.
A.
B.
C.
D.
E.
n=1®n=6
n=6®n=1
n=6®n=3
n=3®n=6
n=1®n=4
Biggest transition = highest energy = highest frequency.
Energy is emitted when going from higher to lower level. Energy is absorbed when going from lower to
higher.
Specific value of energy can be calculated with:
DE = Efinal – Einitial = –2.18x10-18 J
1
–
n2final
1
n2initial
40. What is the maximum number of electrons that can be contained in the n=2 principal quantum level?
A) 2
B) 18
C) 10
D) 8
E) 4
41. How many orbitals (ml values) are allowed in a subshell designated by n=3 and l=2?
A) 5
B) 9
C) 10
D) 18
E) 7
42. What is the shape of an orbital when l = 0?
A)
B)
C)
43. The element Iron (Fe) is atomic number 26. The expected condensed electron configuration of the
Iron 2+ ion (Fe2+) is ___________.
A) [Ar] 4d4
B) [Ar] 4s23d6
C) [Ar] 4s23d4
D) [Ar] 4s13d5
E) [Ar] 3d6
44. Which of the following is the correct ground state condensed orbital diagram for Arsenic (As, atomic
number 33)?
A)
Ar
B)
Ar
C)
Ar
D)
4s
3d
4p
4s
3d
4p
4s
3d
4p
4s
3d
4p
Kr
45. The full electron configuration for Manganese (Mn, atomic #25) is
A) 1s21p61d102s22p5
B) 1s22s22p63s23p64s24d5
C) 1s22s22p63s23p63d7
D) 1s22s22p63s23d104s23d3
E) 1s22s22p63s23p64s23d5
46. Which of the following is an electron configuration of an excited state of an atom?
A) 1s22s22p63s23p2
B) 1s22s22p63s23p4
C) 1s22s22p63s23p64p1
D) 1s22s22p63s23p64s23d3
E) 1s22s22p63s23p2
47. Which of the following would be considered covalent compound?
A) ScCl2
B) Na2S
C) SrCl2
D) OF2
E) K3P
48. Which of the following species in an isoelectronic series has the smallest radius?
A) Ar
B) Ca2+
C) S2D) K+
E) Cl49. You did an experiment in the lab and found the following successive ionization energies
corresponding to an element in the third row of the periodic table:
•
•
•
•
•
•
•
•
IE1 = 325 kJ/mole
IE2 = 385 kJ/mole
IE3 = 425 kJ/mole
IE4 = 470 kJ/mole
IE5 = 490 kJ/mole
IE6 = 6760 kJ/mole
IE7 = 6925 kJ/mole
IE8 = 7135 kJ/mole
Based on this pattern of ionization energies, what is the identity of the element?
A) Mg
B) S
C) P
D) Al
E) Si
50. You found a mystery element in period 2 we will call “X” with the Lewis dot symbol
Of the following choices, what element was it?
A) Be
B) B
C) C
D) N
E) O
X
51. Which of the following ionic compounds has the largest lattice energy, i.e., the hardest to break
apart?
A) KCl
B) CsBr
C) BaO
D) CaS
E) MgO
52. Consider the Lewis structure of GeS2 drawn below. The bond angle between atoms of GeS2 is
_______ and GeS2 will be considered a _________ molecule.
A) 180°, polar
B) 109.5°, polar
C) 180°, nonpolar
D) 109.5°, nonpolar
E) 120°, polar
Ge
S
S
53. Consider the following resonance form of HBrO4. What is the formal charge of the Br atom in this
structure?
A) -1
B) +4
C) +3
D) +2
E) +1
54. There is a formal charge of zero on all of the atoms in which of the following resonance forms of
SO3? C
O
O
A)
B)
S
O
O
S
C)
O
O
O
D) all of them
S
O
E) none of them
O
55. From the given choices, select the best Lewis structure for CN-? C
-
A)
C
N
B)
C
N
C)
C
N
-
D)
C
N
E)
C
N
56. Consider the Lewis structure of BrF5 drawn below. The molecular shape (geometry) of BrF5 is
__________.
A) trigonal bipyramidal
B) square planar
C) octahedral
D) square pyramidal
E) seesaw
F
F
Br
F
F
F
57. Which of the following molecules would belong to the AX3E designation?
A) SF3B) BF3
C) BrF3
D) PF3
E) XeF3+
58. Consider the Lewis structure below. The hybridization of the C atom is ________.
A) sp
B) sp3d2
C) sp3d
D) sp2
E) sp3
O
C
H
H
S
59. The molecule C3H3NO depicted below has ____ sigma (σ) bonds and ____ pi (π) bonds.
O
A) 5 σ, 2 π
B) 10 σ, 3 π
C) 10 σ, 2 π
D) 7 σ, 2 π
E) 7 σ, 3 π
H
C
N
C
H
C
H
60. Consider the following MO diagram for F2-. The bond order is ________ based on this diagram.
σ*2p
π*2p
Energy
A) 0
B) 1
C) 1/2
D) 3/2
E) 2
π2p
σ2p
σ*2s
σ2s
61. Draw the Lewis structure of BrF3. The Br-F bond is considered __________ and the BrF3 molecule is
considered ___________.
Electronegativity values:
Br = 2.96
F = 3.98
A) polar, polar
B) nonpolar, polar
C) polar, nonpolar
D) nonpolar, nonpolar
62. Elements X (green) and Y (purple) react according to the following reaction: X2 +3Y2 → 2XY3
Which molecular scene represents the product of this reaction?
Choice C
63. 19. If 5.67 moles of a gas sample occupy a 17.8 L balloon at 45°C, what is the pressure (in atm) of the
gas sample?
A) 8.32 atm
B) 0.120 atm
C) 7.14 atm
D) 2.63 atm
E) 1.22 atm
Use PV=nRT (pay attention to units)
64. A sample of unknown gas occupies a balloon at 295K and 1.23 atm. If the density of the gas is 3.50
g/L, what is the molar mass of the gas?
A) 839 g/mole
B) 104 g/mole
C) 1270 g/mole
D) 96.5 g/mole
E) 68.9 g/mole
Rearrange PV=nRT to solve for molar mass (MM)
MM = dRT/P
65. Consider the balance reaction: Ni(ClO3)2(s) à NiCl2(s) + 3 O2(g)
How many liters of O2(g) can be formed if 476 grams of Ni(ClO3)2(s) (225.6 g/mole) are consumed in this
reaction at 0.888 atm and 265K?
A) 51.7 L
B) 122 L
C) 117 L
D) 155 L
E) 40.8 L
476 g Ni(ClO3)2(s) x
! =LB? MN(O),/)-(P)
--1.G : MN(O),/)-(P)
x
/ =LB? ,-(.)
! =LB? MN(O),/)-(P)
= 6.33 mole O2(g) = n in PV=nRT
Now use PV=nRT to solve for Volume in L
66. A sample of gas in a balloon has a volume of 375 mL and a pressure of 615 torr at 455K. What is the
new volume (in mL) of the sample if the temperature decreases to 285K and the pressure increases to 875
torr?
A) 643 mL
B) 421 mL
C) 165 mL
D) 260 mL
E) 1560 mL
Consider this table for Questions 67-69:
Container
A
B
C
Gas
Methane
Ethane
Formula
Molar mass
(g/mol)
CH4
C2H6
Butane
CH
4 10
16
30
58
Temperature
( C)
27
27
27
Pressure (atm)
2.0
4.0
2.0
67. Container A and C have the same temperature and pressure. Which contains the gas with the
greatest density?
A) Container A
B) same in both
C) Container C
Greater molar mass means greater density at the same temperature and pressure.
68. The average speed of the gas molecules is:
A. Highest in container A
B. Highest in container B
C. Highest in container C
D. the same in all three containers
Lowest molecular weight equates to highest average speed.
69. The average kinetic energy of the gas molecules is
A. Highest in container A
B. Highest in container B
C. Highest in container C
D. the same in all three containers
Average kinetic energies of gases at the same temperature are equal.
70. The graph to the left shows the speed distribution of molecules in a sample of a gas at a certain
temperature. Which of the graphs to the right shows the speed distribution of the same molecules at a
lower temperature (as a dashed curve)?
Lowest Choice: lower average speed at a lower temperature