CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
Instructions
1) Do NOT wait to complete this practice exam until the night before the actual exam!
2) Look over the practice exam before you finish studying so you can see the type of questions that you will be
asked, and so you know the format and length of the exam.
3) Do NOT waste your time memorizing the answers to these problems!
 The problems on the real exam will be different
 Look at the end of the course syllabus. There is an outline of the course material. Any course material on
the syllabus is fair game for the real exam even if it does not appear on this practice exam.
4) Check your work with the answer key (posted as a separate file). The answer key includes detailed
calculations.
The answer key will be posted once all sections have a course evaluation completion rate ≥ 60%.
THERE IS AN EQUATION SHEET, A TABLE OF ELECTRONEGATIVITY VALUES, AND A
PERIODIC TABLE AT THE END OF THE PRACTICE EXAM.
YOU WILL GET THE SAME INFORMATION ON THE REAL EXAM.
SUMMER 2022
The final exam will be graded 100% based on correctness.
NO EFFORT CREDIT.
Prof. Surry will NOT look at your exam paper at all. The only
thing she will look at is your Scantron!
Bring a PENCIL and an ERASER to the exam.
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CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
Problems #1 and #2 will refer to this chemical equation:
Na (s) + H2 O (l) →
NaOH (aq) + H2 (g)
Balance the chemical equation, then answer the questions.
1. Which of the following statements are TRUE about this
reaction?
I.
II.
III.
IV.
V.
VI.
This reaction is not spontaneous at 25 ℃.
This reaction is endothermic.
∆S = 12 J/mol ∙ K
∆S < 0
The aqueous solution on the product side has pH < 7.
This reaction is exothermic.
A) II, III, V
B) I, II, and III
C) IV and VI
D) II and V
E) I, II, IV
2. In this reaction:
I.
II.
III.
IV.
V.
The sodium was oxidized.
Work is done on the system, by the surroundings.
The reaction vessel would feel hot.
∆G = −838.4 kJ/mol
∆H = ∆U
A) I and III
B) None of these statements are true.
C) IV and V
D) II, III, and V
E) I and IV
3. Which of the following statements are TRUE about this chemical reaction:
BaCl2 (aq) + Na2 SO4 (aq) → Products
I. This is a redox reaction
II. This is an acid/base reaction
III. The products are BaNa2 and Cl2 SO4
IV. The product is an aqueous solution containing four different aqueous ions.
V. On the reactant side, the cations are isoelectronic with Ar and Rn.
A) I and II
B) III and IV
C) II and V
D) IV only
E) None of these statements are true.
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CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
Problems #4, #5, and #6 will refer to this chemical equation:
NOBr (g) ⇌ NO (g) + Br2 (g)
Balance the equation, then answer the questions.
4. Which of the following statements are TRUE?
I.
II.
III.
IV.
V.
One of the products is not a compound.
The reactant is an ionic compound.
The equilibrium law for this reaction does not contain Br2 .
The NO molecule has an unpaired electron.
All of the substances in this reaction are polar.
A) I and IV
B) III and V
C) II and III
D) I, IV, and V
E) I and II
5. At 36 ℃, 41% of the NOBr has dissociated into nitric oxide (nitrogen monoxide) and Br2 . The total pressure of the
system is 0.25 atm. What is the partial pressure of nitric oxide?
A) 0.207 atm
B) 0.1025 atm
C) 0.105 atm
D) 0.085 atm
E) 1.2 atm
6. At 36 ℃, 41% of the NOBr has dissociated into nitric oxide (nitrogen monoxide) and Br2 . The total pressure of the
system is 0.25 atm. What is K p for this reaction?
A) 2.1 x 10−2
B) 4.1 x 10−1
C) 2.05 x 10−1
D) 2.48 x 102
E) 1.56 x 103
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CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
Problems #7, #8, and #9 will refer to this chemical equation:
Al (s) + HBr (aq) → AlBr3 (aq) + H2 (g)
Balance the equation, then answer the questions.
7. The net ionic equation for this reaction is:
A) None of these are correct.
B) Al (s) + 2 H + (aq) → Al2+ (aq) + H2 (g)
C) 2 Al (s) + 6 H + (aq) → 2 Al3+ (aq) + 2 H2 (g)
D) 2 Al (aq) + 6 H + (aq) + 6 Br − (aq) → 2 Al3+ (aq) + 6 Br − (aq) + 3 H2 (g)
E) Al (s) + 2 H + (aq) → Al3+ (aq) + H2 (g)
o
8. Use the following data to compute ∆Hrxn
:
Substance
Al (s)
HBr (𝑔)
AlBr3 (s)
H2 (g)
H + (aq)
Br − (aq)
Al3+ (aq)
∆Hfo (kJ/mol)
0
−36.2
−572.5
0
0
−120.9
−524.7
S o (J/mol ∙ K)
28.3
198.5
180.2
131.0
0
80.7
−313.4
A) −524.7 kJ/mol
B) −572.5 kJ/mol
C) −1145.0 kJ/mol
D) −927.8 kJ/mol
E) −1049.4 kJ/mol
9. Is this reaction spontaneous at 25 ℃?
A) This cannot be determined from the information provided
B) No, because ∆Grxn > 0
C) Yes, because ∆Grxn > 0
D) Yes, because ∆Grxn < 0
E) No, because ∆Grxn < 0
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CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
Problems #10, #11 and #12 will refer to this balanced chemical equation:
CaCO3 (s) ⇌ CaO (s) + CO2 (g)
∆H = 178 kJ/mol
10. Which of the following changes would decrease the amount of calcium oxide present at equilibrium?
I.
II.
III.
IV.
V.
Increase the temperature
Add more carbon dioxide
Increase the pressure by decreasing the volume
Decrease the temperature
Remove the carbon dioxide as it forms
A) II, III, and IV
B) III, IV, and V
C) III only
D) II only
E) I and V
11. At 1200 ℃, K p = 0.486 for this reaction. What is the partial pressure of carbon dioxide once the equilibrium has been
established at 1200 ℃?
A) 2.68 x 10−3 atm
B) 20.8 atm
C) 4.86 x 10−1 atm
D) 0.236 atm
E) This cannot be determined from the information provided.
12. Which of these statements are TRUE about this reaction?
I.
II.
III.
IV.
V.
The calcium is the reducing agent.
The anion on the product side is isoelectronic with neon.
The cation on the reactant side has 18 protons.
The carbon dioxide molecule has a 180 bond angle.
This is an acid/base reaction.
A) I and II
B) III only
C) II and IV
D) III and V
E) II, IV, and V
13. Which of the following statements are TRUE if you have a 1.5 g sample of calcium carbonate and a 1.5 g sample of
calcium oxide?
I.
II.
III.
IV.
The samples contain the same number of moles of calcium.
The calcium carbonate sample has a lower weight percent of calcium.
The calcium oxide sample has a higher weight percent of oxygen.
The samples contain the same number of grams of calcium.
A) I and III
B) II and IV
C) II only
D) I, III, and IV
E) All of these statements are true.
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CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
Problems #14, #15, and #16 will refer to this chemical equation:
HA (aq) + H2 O(l) ⇌ H3 O+ (aq) + A− (aq)
Acid
HF
HCl
HBr
HI
𝑲𝒂 _____
7.1 x 10−4
1.3 x 106
1.0 x 109
3.2 x 109
14. What do the reactions of HF, HCl, HBr, and HI with water all have in common?
A) The equilibrium favors the reactant side.
B) The conjugate acid is hydronium.
C) The conjugate acid is chloride.
D) The conjugate base is hydronium.
E) The equilibrium favors the product side.
15. Which of the following statements are TRUE about a 0.10 M solution of HF and a 0.10 M solution of HCl?
I.
II.
III.
IV.
V.
The pH of the HF solution is greater than 1.00.
The pH of the HF solution is 1.00
These solutions have the same pH
The HCl solution has a lower pH than the HF solution
Neither of these solutions contains any hydroxide.
A) I and IV
B) I, IV, and V
C) III only
D) II and III
E) I and II
16. Which of the following species will be present in a 0.10 M solution of HCl?
I.
II.
III.
IV.
HCl molecules
Water molecules
Hydronium ions
Chloride ions
A) I and II
B) III and IV
C) II, III, and IV
D) I and III
E) I, II, III and IV
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CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
Problems #17, #18, and #19 will refer to this procedure:
Titration was used to determine the molar mass of an unidentified monoprotic acid, HA.
Step 1: 2.0 g of NaOH was combined with 500 mL of water to prepare NaOH (aq).
Step 2: The NaOH (aq) was standardized using 0.5117 g of KHP (KHC8 H4 O4 , MW = 204.22 g/mol). The quantity of
NaOH (aq) that was needed to reach the endpoint was 28.92 mL.
KHC8 H4 O4 (aq) + NaOH (aq) → NaKC8 H4 O4 (aq) + H2 O (l)
Step 3: A sample of HA with a mass of 0.6346 g was dissolved in 40.0 mL of water in an Erlenmeyer flask. This
solution was titrated with the standardized NaOH (aq) from Step 2 and 39.30 mL of NaOH (aq) was needed to reach
the endpoint.
HA (aq) + NaOH (aq) → NaA (aq) + H2 O (l)
17. What is the molar mass of HA?
A) 403.0 g/mol
B) 186.4 g/mol
C) 16.0 g/mol
D) 242.1 g/mol
E) 100.0 g/mol
18. The titration of 0.6346 g if HA with the standardized NaOH requires 39.30 mL of NaOH to reach the endpoint. If the
student overshot the titration and added 41.00 mL of NaOH instead, what would be the approximate pH of the final
solution in the flask?
A) 11.26
B) 7.61
C) 2.74
D) 12.44
E) 14.80
19. The problem stated that the unidentified acid was monoprotic (HA). If everything else was the same, but the acid was
triprotic (H3 A), how would the molar mass that you computed in Problem #17 change?
A) The molar mass would decrease.
B) The molar mass would triple.
C) The molar mass would stay the same.
D) The molar mass would double.
E) This cannot be determined from the information provided.
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CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
Problems #20, #21, and #22 will refer to this chemical equation:
Br2 (g) ⇌ 2 Br (g)
20. Which of the following statements are TRUE about this chemical equation?
I.
II.
III.
IV.
V.
This is a precipitation reaction.
On the product side, the Br has 8 valence electrons.
This is an endothermic process.
There is a triple bond in the Br2 molecule.
This equation represents a phase change.
A) I and IV
B) IV only
C) II and III
D) II, III and V
E) III only
21. At 1600 ℃, 1.20% of bromine molecules dissociate into neutral bromine atoms. What is K C for the reaction of 76.0 g
of Br2 in a 2.00 L flask?
A) 1.39 𝑥 10−4
B) 2.43 x 10−2
C) 3.345 x 103
D) 1.20 x 10−2
E) 2.99 x 10−4
22. An equilibrium was established in a container with a volume of 2.00 L at 1600 ℃. Which of the following changes
would result in the equilibrium shifting towards the product side of the reaction?
A) Increasing the volume of the container while holding the temperature constant.
B) Decreasing the temperature while holding the volume constant.
C) Decreasing the volume of the container
D) Adding more neutral bromine atoms
E) Removing some of the bromine molecules
23. Which of the following sets of quantum numbers are valid for a valence electron in a neutral bromine atom?
A) 𝑛 = 3, 𝑙 = 0, 𝑚𝑙 = 0, 𝑚𝑠 = +1/2
B) 𝑛 = 2, 𝑙 = 1, 𝑚𝑙 = 2, 𝑚𝑠 = −1/2
C) 𝑛 = 4, 𝑙 = 0, 𝑚𝑙 = 0, 𝑚𝑠 = +1/2
D) 𝑛 = 4, 𝑙 = 2, 𝑚𝑙 = −1, 𝑚𝑠 = −1/2
E) None of them.
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CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
Problems #24, #25, #26, and #27 will refer to these thermochemical equations:
H2 O (s) ⇌ H2 O (l)
∆Hfus = 6.01 kJ/mol
H2 O (l) ⇌ H2 O (g)
∆Hvap = 44.0 kJ/mol
24. What is the enthalpy change when 110 g of water vapor condenses into liquid water at 100 ℃?
A) −305 kJ
B) 44.0 kJ
C) 6.01 kJ
D) −269 kJ
E) 2.5 kJ
25. What additional information would you need to calculate the heat change for the following process?
53 g H2 O (s), −15 ℃ → 53 g H2 O (g), 110 ℃
A) No additional information
B) The specific heats of H2 O (s), H2 O (l), and H2 O (g)
C) The heat capacity of ice
D) ∆Hfo for H2 O
E) The volume of the container and the external pressure
26. Which of the following statements are true about water in the solid phase?
I.
II.
III.
IV.
V.
Each water molecule is a trigonal planar shape.
If the sample were melted, the density would decrease.
If the sample were melted, the entropy would increase.
The water molecules are held together by dispersion forces only.
The bond angle on each water molecule is 120˚
A) II, III, and IV
B) I, III, and V
C) I, II, III, and V
D) III only
E) II and IV
27. Consider the substance H2 S (hydrogen sulfide). Which of the following predictions can you make, based on what you
already know about H2 O?
I.
II.
III.
IV.
V.
∆Hvap < 44.0 kJ/mol
∆Hvap > 44.0 kJ/mol
The normal boiling point is less than 100˚C.
The normal boiling point is greater than 100˚C.
At the normal boiling point, the vapor pressure of H2 S is 1 atm
A) V only
B) I and III
C) I, III, and V
D) I and IV
E) II, IV, and V
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CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
Problems #28, #29, and #30 will refer to this chemical equation:
(NH4 )HS (s) ⇌
NH3 (g) + H2 S (g)
Balance the chemical equation, then answer the questions.
An evacuated 2.00 L vessel was charged with 2.1052 g of the solid. An equilibrium was established at 10.0 ℃ and the
total pressure inside the vessel was 0.140 atm at equilibrium. Some of the solid remained.
28. What is 𝐾𝑝 for this reaction?
A) 1.26 𝑥 10−1
B) 1.75 𝑥 10−1
C) 3.06 𝑥 10−2
D) 3.50 𝑥 10−1
E) 4.90 𝑥 10−2
An evacuated 2.00 L vessel was charged with 2.1052 g of the solid. An equilibrium was established at 10.0 ℃ and the
total pressure inside the vessel was 0.140 atm at equilibrium. Some of the solid remained.
29. What percentage of the solid has reacted?
A) 21.5%
B) 74.3%
C) 100%
D) 48.2%
E) 11.1%
30. If the volume of the reaction vessel were halved, at a constant temperature, what would happen to the amount of solid
present?
A) It would increase
B) It would decrease
C) It would stay the same
D) It would increase by exactly 25%
E) It would decrease by exactly 50%
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CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
31. Consider the substance diethyl ether (C4 H10 O). This substance does NOT experience intermolecular hydrogen
bonding. Based on this information, which of these Lewis Structures is the structure of diethyl ether?
32. ∆Hvap = 26.0 kJ/mol for diethyl ether (C4 H10 O). The vapor pressure of diethyl ether is 0.528 atm at 18.0 ℃. What is
the vapor pressure of diethyl ether at 25.0 ℃?
A) 0.955 atm
B) 0.528 atm
C) 0.679 atm
D) 7.07 x 1020 atm
E) 1.6 x 10−11 atm
33. Which of the following statements are TRUE about diethyl ether (C4 H10 O)?
I.
II.
III.
IV.
V.
This substance is a gas at 25 ℃ when the external pressure is 1 atm
This is an ionic compound
The normal boiling point of this substance is less than 25 ℃
The normal boiling point of this substance is greater than 25 ℃
The substance is a liquid at 25 ℃ when the external pressure is 1 atm
A) IV and V
B) I and II
C) II and III
D) I and III
E) III and V
11
CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
Approximate Electronegativity Values
12
CM 1003 – General Chemistry for Engineers
Equation Sheet
x=
Practice Exam for the Final Exam
TEAR THIS PAGE OFF OF YOUR EXAM
− 𝑏 ± √𝑏2 −4𝑎𝑐
2𝑎
isolated yield
% yield = theoretical yield x 100%
ax2 + bx + c = 0
𝑚𝑜𝑙𝑒𝑠 𝑜𝑓 𝑠𝑜𝑙𝑢𝑡𝑒
molarity (M) = 𝑙𝑖𝑡𝑒𝑟𝑠 𝑜𝑓 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛
M1V1 = M2V2
P1V1 = P2V2
101.33 J = 1 L∙atm
0.00 oC = 273.15 K
𝑉1 𝑉2
=𝑇
𝑇1
2
𝑃1
𝑃
= 𝑇2
𝑇1
2
R = 8.314 𝑚𝑜𝑙 𝐾
PV = nRT
d = 𝑅𝑇
𝑋𝑖 = 𝑛 𝑖
1.00 atm = 760. mmHg = 760. torr
U = q + w
w = − PV
H = U + PV
H = U + PV
U = H – RTn
C = ms
q = mst
q = Ct
𝐽
∆𝐻𝑣𝑎𝑝
𝑅𝑇
𝐿 𝑎𝑡𝑚
R = 0.0821 𝑚𝑜𝑙 𝐾
𝑃𝑀
𝑛
𝑇
𝑜
𝐻𝑟𝑥𝑛
= ∑n 𝐻𝑓𝑜 (products) − ∑m 𝐻𝑓𝑜 (reactants)
ln P = −
Version B
𝑃
ln 𝑃1 =
+𝐶
2
∆𝐻𝑣𝑎𝑝 𝑇1 − 𝑇2
(𝑇𝑇 )
𝑅
1 2
𝑍𝑒𝑓𝑓 = Z − 
𝐻𝑠𝑢𝑏 = 𝐻𝑓𝑢𝑠 𝐻𝑣𝑎𝑝 
[𝐶]𝑐 [𝐷]𝑑
𝑃1 = 𝑋1 𝑃1𝑜
K = [𝐴]𝑎[𝐵]𝑏
𝐾𝑤 = [H+][OH-] = 1.0 x 10−14 pH = − log[H+]
𝑆𝑢𝑛𝑖𝑣𝑒𝑟𝑠𝑒 = 𝑆𝑠𝑦𝑠 + 𝑆𝑠𝑢𝑟𝑟 > 0
G = H – TS
G = H – TS
𝐾𝑝 = 𝐾𝑐 (0.0821 𝑇)∆𝑛
pH + pOH = 14.00
𝑜
𝑆𝑟𝑥𝑛
= ∑n 𝑆 𝑜 (products) − ∑m 𝑆 𝑜 (reactants)
𝑜
𝐺𝑟𝑥𝑛
= ∑n 𝐺𝑓𝑜 (products) − ∑m 𝐺𝑓𝑜 (reactants)
Solubility Rules
Soluble Compounds
Containing:
Alkali metal ions
Halides
Ammonium
Sulfates
Nitrates
Exceptions:
Insoluble Compounds
Containing:
Carbonates
Phosphates
Sulfides
Hydroxides
PbX2 (lead halides), silver halides, and sulfates of calcium, barium, lead, and silver are insoluble.
Hydroxides of alkali metal ions and barium hydroxide are soluble.
Carbonates, phosphates, and sulfides of alkali metal ions or ammonium are soluble.
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CM 1003 – General Chemistry for Engineers
Practice Exam for the Final Exam
Version B
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