Midterm Exam 2A (White)
Name_______________________________
Minneapolis Community and Technical College
CHEM 1151 Spring 2017 ...Boraas
Administrative Use Only
Lab Sec.(circle one)
8:15am
2:30pm
5:30pm
Scantron: ______ + SW ______ = ________
Directions:
1. Write your name at the top of this exam (No chemical symbols).
2. Record your name and the exam version (A or B) on the scantron answer sheet.
3. Record your answer to each question on the Scantron answer sheet IN PENCIL.
4. Return this exam and all materials including your notecard with your answer sheet.
Failure to do so at the time of the exam will result in a zero for the exam.
5. Scantron answer sheets will be graded as received and not reviewed for erasures, smudges or anything else that may
result in a mis-graded form. Make no stray marks or smudges on the scantron answer sheet. If you must erase, do so
completely.
6. If you believe your scantron answer sheet will not grade properly, ask for a new, clean scantron answer sheet.
7. Always choose the closest answer.
1. E (Chapter 1) While driving my car down the highway I notice a strange vibration in the steering wheel.
Thinking that I have a bad tire, I drive to a local tire garage and have them check all four wheels.
The underlined text above is an example of …
a. an experiment
b. a model
c. a law
d. an observation
e. a hypothesis
2. B (Chapter 1) What answer should be reported, with the correct number of significant
figures, for the calculation at right?
a. 4.6
b. 4.57
c. 4.573
d. 4.5728
e. 4.57277
3. D (Chapter 1) What is the chemical symbol for tungsten?
a. Tu
b. Tg
c. T
d. W
e. K
4. B (Chapter 1) Read the water level in the graduated cylinder at right with the correct number of significant
figures.
a. 5 mL
b. 5.3 mL
c. 5.32 mL
d. 5.320 mL
e. 5.3200 mL
5. D (Chapter 1) Convert 65.0 oF to Kelvins. (Closest Answer Please)
a. 327 K
b. 310 K
c. 305 K
d. 291 K
e. 254 K
6. A(Chapter 1) A cube weighs 100. grams and measures 5.00 cm on each side. Determine the density of the
block and decide which of the following statements is true.
a. 0.800 g/cm3 and the block will float on water
c. 1.25 g/cm3 and the block will float on water
b. 0.800 g/cm3 and the block will sink in water
d. 1.25 g/cm3 and the block will sink in water
7. D (Chapter 2) What charge would a calcium ion most likely have?
a. 6b. 2c. 3+
d. 2+
e. 1+
8. C (Chapter 2) How many electrons are represented by silver’s nuclide symbol at right?
a. 106 eb. 107 ec. 46 ed. 47 ee. 48 e9. C (Chapter 2) How many individual gold atoms are there in 2.87 moles of gold?
a. 6.22 × 1023 gold atoms
b. 2.26 × 1024 gold atoms
23
d. 2.10 × 10 gold atoms
e. 6.50 × 1025 gold atoms
c. 1.73 × 1024 gold atoms
isotope
10. C (Chapter 2) An element has three different isotopes (table at right):
X – 22
If the average atomic mass is 22.9488 amu, what is the mass
X – 23
of the X-22 isotope?
X – 25
What is the average atomic mass? (Closest answer please)
a. 21.4299 amu
b. 21.8432 amu
c. 21.7444 amu
d. 22.0341 amu
e. 22.1455 amu
11. B(Chapter 2) What is the mass (g) of 5.45 moles of copper?
a. 334 g
b. 346 g
c. 358 g
d. 372 g
12. C (Chapter 2) Calculate the mass (in kg) of 1.55 x 1026 atoms of potassium.
e. 144 g
mass (amu)
?
22.9374
24.9285
Abundance
49.885 %
19.654%
30.461%
a. 2.88 kg
b. 8.41 kg
c. 10.1 kg
d. 11.3kg
13. C (Chapter 3) What is the correct name for CuSO4?
a. Copper sulfide
b. Copper (I) sulfate
d. Copper sulfur tetroxide
e. no correct answer
14.B (Chapter 3) What type of chemical bonding is found in ZnI2?
a. metallic bonding
b. ionic bonding
15. E (Chapter 3) Determine the name for N2O5.
a. nitrogen pentoxide
d. nitrogen (II) oxide
e. 14.8 kg
c. Copper (II) sulfate
c. covalent bonding
b. nitrogen oxide
e. dinitrogen pentoxide
d. James Bonding
c. nitrogen (II)oxide(IV)
16. A (Chapter 3) Calculate the mass percent composition of sulfur in Al2(SO4)3.
a. 28.12 %
b. 9.372 %
c. 42.73 %
d. 21.38 %
e. 35.97 %
17. C (Chapter 3) Determine the molecular formula of a compound that has a molar mass of 92.0 g/mol
and an empirical formula of NO2.
a. N2O3
b. N3O6
c. N2O4
d. NO2
e. N2O5
18. D (Chapter 3) Aqueous lead (II) nitrate reacts with aqueous potassium chloride to form solid lead (II) chloride
and aqueous potassium nitrate.
Which of the following equations correctly describes the word equation above?
a. PbNO3(aq)
b. PbN (aq)
c. Pb(NO3)2(aq)
d. Pb(NO3)2(aq)
e. PbNO3(aq)





+ 2 KCl(aq)
+
KCl(aq)
+ 2 KCl(aq)
+ 2 KCl(aq)
+
KCl(aq)
PbCl2(s)
PbCl (s)
PbCl2(s)
PbCl2(s)
PbCl (s)
+
+
+
+
+
KNO3(aq)
KN (aq)
K2(NO3)2(aq)
2KNO3(aq)
KNO3(aq)
19. D (Chapter 3) Balance the following chemical equation:
Cr2(SO4)3(aq) + RbOH (aq) 
Cr(OH)3(aq) +
Rb2SO4 (aq)
What is the coefficient belonging to RbOH in the final, balanced chemical equation?
a. 2
b. 3
c. 5
d. 6
e. 9
20. E (Chapter 4) Consider the following balanced reaction. How many moles of oxygen are required to produce 2.33 moles of
water?
C3H8S (l) + 6 O2(g) → 3 CO2(g) +
a. 1.55 moles O2
b. 4.14 moles O2
SO2(g) +
c. 2.33 moles O2
4 H2O (g)
d. 3.21 moles O2
e. 3.50 moles O2
21. B (Chapter 4) Examine the following balanced chemical equation and initial reactant moles. What is the limiting reactant?
a. Cr2O3(s)
Cr2O3(s) +
3 H2S(g)
3 moles
8 moles
b. H2S(g)

c. Cr2S3(s)
Cr2S3(s)
0 moles
d. H2O(l)
+
3 H2O(l)
0 moles
e. There is no one limiting reactant.
22. C (Chapter 4) What is the concentration of chloride ions in a 0.125 M FeCl3 solution?
a. 0.125 M
b. 0.0625 M
c. 0.375 M
d. 0.250 M
e. 0.160 M
23. A (Chapter 4) Determine the concentration of the solution formed when 25.0 mL of 0.188 M Ca(NO 3)2 solution is mixed
with 125.0 mL of distilled water.
a. 0.0313 M
b. 0.0887 M
c. 1.13 M
d. 0.0376 M
e. 0.0501 M
24. A (Chapter 4) (Chapter 4) In the following balanced chemical equation, what is oxidized?
H2(g)
3 Fe(s) + 4 H2O(g)  Fe3O4(s) + 4
a. Fe(s)
b. H2O(g)
c. Fe3O4(s)
d. H2(g)
25. C (Chapter 4) Given the problem outlined at right determine which of
the following dimensional analysis solutions is correct.
26. C (Chapter 4) What is the CO2 theoretical yield (moles) if 4.00 moles of C8H18 reacts with 4.00 moles of O2 according to the
following balanced reaction:
2 C8H18
a. 0.320 moles
+
25 O2
→ 16 CO2
b. 32.0 moles
+
18 H2O
c. 2.56 moles
d. 16.0 moles
27. A (Chapter 4) Examine the following total molecular equation:
FeSO4(aq)
+
Ba(OH)2(aq)

Fe(OH)2(s)
+
BaSO4(s)
What is the correct net ionic equation?
a. Fe2+(aq) + SO42–(aq) + Ba2+(aq) + 2 OH–(aq)
b. Fe2+(aq) + 2 OH–(aq)
c. SO42–(aq) + Ba2+(aq)
d. Fe2+(aq) + SO42–(aq) + Ba2+(aq) + 2 OH–(aq)
 Fe(OH)2(s) + BaSO4(s)
 Fe(OH)2(s)
 BaSO4(s)
 FeSO4 (s) + Ba(OH)2(s)
28. B (Chapter 5) A 0.29 moles sample of Ar gas occupies 3.8 L. What volume will 0.66 moles occupy under the same conditions?
a. 12 L
b. 8.6 L
c. 17 L
d. 5.0 L
e. 15 L
29. A (Chapter 5) How many moles of CO gas fill a 5.00 L gas tank at 155°C and 2.80 atm?
a. 0.399 moles
b. 1.10 moles
c. 2.51 moles
d. 0.455 moles
e. 0.289 moles
30. D (Chapter 5) In the graph pictured at right, what letter corresponds to
the gas velocity distribution with the highest temperature?
31. C (Chapter 5) Which statement is TRUE about the kinetic molecular theory?
a. A single particle moves along curved paths.
b. The size of the particle is large compared to the volume.
c. Particle collisions are completely elastic.
d. The average kinetic energy of a particle is does not depend on the temperature.
32. B (Chapter 5) A mixture of 0.220 moles CO, 0.350 moles H2 and 0.640 moles He has a total pressure of 2.95 atm.
What is the partial pressure of CO?
a. 1.86 atm
b. 0.536 atm
c. 0.649 atm
d. 1.54 atm
e. 0.955 atm
33. E (Chapter 5) Which of the following gases is least like an ideal gas?
a. Ne
b. Ar
c. CO 2
d. N2
e. CCl4
34. A (Chapter 6) A sample of copper absorbs 43.6 kJ of heat, resulting in a temperature rise of 75.0 °C, determine the mass (in kg) of
the copper sample if the specific heat capacity of copper is 0.385 J/g°C.
a. 1.51 kg
b. 6.62 kg
c. 1.26 kg
d. 7.94 kg
e. 3.64 kg
35. A(Chapter 6) 255 J of heat energy flows from the surroundings into a system. At the same time, the system does 428 J of work.
What is the change in internal energy (E) of the system in joules?
a. -173 J
b. -255 J
c. -428 J
d. -683 J
e. – 1000 J
36. D (Chapter 6) Which of the following signs on q and w represent
a system that is doing work on the surroundings and losing heat to the surroundings?
a. Positive “q”
and Negative “w”
b. Positive “q”
and Positive “w”
c. Negative “q”
and Positive “w”
d. Negative “q”
and Negative “w”
37. E (Chapter 6) Use the standard reaction enthalpies given below to determine ΔH°rxn for the following reaction:
GOAL:
P4(g) + 10 Cl2(g) → 4PCl5(s)
ΔH°rxn = ?
Given:
PCl5(s)
ΔH°rxn= +157 kJ
Given:
P4(g) + 6 Cl2(g)
a. -2100. kJ
→ PCl3(g) + Cl2(g)
→ 4 PCl3(g)
b. -1364 kJ
ΔH°rxn= -1207 kJ
c. -1050. kJ
d. -1786 kJ
e. -1835 kJ
38.C (Chapter 6) Use the ΔH°f information provided below to calculate ΔH°rxn for the following:
SO2Cl2 (g) + 2 H2O(l) → 2 HCl(g) + H2SO4(l)
ΔH°f
SO2Cl2(g)
H2O(l)
HCl(g)
H2SO4(l)
a. -256 kJ
b. +161 kJ
ΔH°rxn = ?
-364 kJ/mol
-286 kJ/mol
-92 kJ/mol
-814 kJ/mol
c. -62 kJ
d. +800. kJ
e. -422 kJ
39) B (Chapter 6) A 4.98 g sample of aniline (C6H5NH2, molar mass = 93.13 g/mol) was burned in a bomb calorimeter with a heat
capacity of 4.25 kJ/°C. If the temperature rose from 29.5°C to 69.8°C, determine the value of ΔH° comb for aniline.
a. +7.81 × 103 kJ/mol
d. -1.71 × 103 kJ/mol
b. -3.20 × 103 kJ/mol
e. -7.81 × 103 kJ/mol
c. +1.71 × 103 kJ/mol
40. C` (Chapter 6) A 50.0 gram aluminum sample is heated to 87.0 oC and then placed in a calorimeter containing 350. grams of
water. If the water’s initial temperature is 23.0 oC, what is the final temperature of the system?
H2O specific heat = 4.184 J/goC
a. Tf = 22.8 oC
b. Tf = 23.8 oC
Aluminum specific heat = 0.900 J/goC
c. Tf =24.9 oC
d. Tf =25.1 oC
e. Tf =26.5 oC
Show all work neatly for full credit.
Answers must be circled, adjusted for significant figures and appear with correct units.
41. (5 pts) Oxygen gas was produced in the laboratory
by decomposing solid KClO3:
2 KClO3(s) → 2 KCl(s) + 3 O2(g)
During the experiment, laboratory conditions were
Patm = 759 torr and TLab= 18.7oC.
If 235.0 mL of O2 is collected over water,
how many grams of KClO3 decomposed?
42. (5 pts)
Show all work neatly for full credit.
Answers must be circled, adjusted for significant figures and appear with correct units.
Combustion
analysis of 63.8 mg of a C, H and O containing compound produced
145.0 mg of CO2 and 59.32 mg of H2O. What is the empirical formula for the compound?
43. (5 pts) 45.7 g N2 Show all work neatly for full credit.
Answers must be circled, adjusted for significant figures and appear with correct units.
60.0 g N2O4 and 45.0 g N2H4 are reacted via the following chemical reaction:
N2O4(l) + 2 N2H4(l) → 3 N2(g) +
4 H2O(l)
If 35.0 grams of water are actually produced, calculate the theoretical AND percent yields.
Bonus Problems. Show all work.
(+2 pt).
Sodium sulfide and zinc sulfate solutions are combined and a solid precipitate observed,
What is the net ionic equation for this situation?
(+2 pt) 20.25 mL of 1.75 M NaOH were used to titrate 45.00 mL of phosphoric acid, H3PO4. What is the concentration of the acid?
NaOH(aq) +
H3PO4(aq)

H2O(l)
+ Na3PO4(aq)