Practice Midterm
Version 1 Seat:________
MCGILL UNIVERSITY FACULTY OF SCIENCE DEPARTMENT OF CHEMISTRY
Midterm CHEMISTRY 222/234 Friday July 19th, 2013 Lea 219 6:00 – 9:00 pm
____________________________________________________________________________ LAST NAME FIRST NAME STUDENT NUMBER Time 6:00 – 9:00 pm
EXAMINERS: Professor Laura Pavelka INSTRUCTIONS: 1.
Fill in your full name and student ID number on the scantron sheet provided.
2.
Answer all multiple choice (Part 1) questions on the scantron sheet provided and answer all of the short answer (Part 2) questions in the exam booklet.
3.
Fill in the appropriate circles (darkly) on the scantron for youranswers to the multiple choice questionss only when you are sure of your response. Pens or pencils are ok.
4.
Put your name on the first page of the exam booklet and hand it in along with the scantron sheet at the end of the exam. There must be an answer sheet and an exam for each student.
5.
A periodic table, IR frequency charts, and NMR chemical shift range charts are provided as the end of the exam booklet.
6.
Molecular model kits are permitted and, for students who use English as a second language, dictionaries are permitted.
7.
THE EXAMINATION SECURITY MONITOR PROGRAM DETECTS PAIRS OF STUDENTS WITH UNUSUALLY SIMILAR ANSWER PATTERNS ON MULTIPLE-CHOICE EXAMS. DATA GENERATED BY THIS PROGRAM CAN BE USED AS ADMISSIBLE EVIDENCE, EITHER TO INITIATE OR CORRROBORATE AN INVESTIGATION OR CHARGE OF CHEATING UNDER SECTION 16 OF THE CODE OF STUDENT CONDUCT AND DISCIPLINARY PROCEDURES.
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Page 2 of 19 Part A: Multiple Choice (30 questions – 2 marks each) 1. The strongest of the intermolecular forces is which of the following? A) Dipole-dipole B) Dispersion forces C) Hydrogen bonds D) Ion-dipole E) Cation-anion
2. For the following reaction, what significant change(s) would be expected in the IR spectrum of the ether compared to that of the starting material (alcohol), ignoring any CH absorptions?
A) A peak around 2150 cm-1 would disappear and a new peak around 3300 cm-1 would appear. B) A peak around 3300 cm-1 would disappear. C) No change would be observed. D) A peak around 3300 cm-1 would disappear and a new peak around 1710 cm-1 would appear. E) None of these
3. The IR spectrum of which type of compound will not show evidence of hydrogen bonding? A) Phenol B) Carboxylic acid C) Primary amine D) Alcohol E) Aldehyde
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Page 3 of 19 4. For the functional group on the following molecule, what characteristic IR absorption would be expected, ignoring C-H absorptions?
A) B) C) D) E)
A peak around 1650 cm-1 A peak around 2250 cm-1 A peak around 3300 cm-1 A peak around 1700 cm-1 None of these
5. Which molecule would have a dipole moment greater than zero? A) H2O B) CO2 C) CCl4 D) BCl3 E) BeCl2
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Page 4 of 19 6. What is the most likely molecule that would give rise to the following IR spectrum?
A)
B)
C)
D)
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Page 5 of 19 7. What is the most likely molecule that would give rise to the following IR spectrum?
A)
B)
C) D)
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Page 6 of 19 8. What is the most likely molecule that would give rise to the following IR spectrum?
A) B) C) D)
9. For the following compound, how many different signals would you expect to see in the 1 H NMR spectrum?
A) B) C) D) E)
5 3 2 6 4
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Page 7 of 19 10. For the following compound, how many different signals would you expect to see in the 1 H NMR spectrum?
A) B) C) D) E)
5 7 8 6 4
11. In NMR terminology, what classification do we give HA and HB?
A) B) C) D) E)
enantiotopic protons. isomeric protons. vicinal protons. homotopic protons. diastereotopic protons.
12. The 1H NMR signal for which of the indicated protons occurs farthest downfield?
A) B) C) D) E)
HE HD HA HC HB
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Page 8 of 19 13. In NMR terminology, what classification do we give HA and HB?
A) B) C) D) E)
Homotopic Heterotopic Enantiotopic Diastereotopic Identical
14. The 13C NMR signal for which of the indicated (bolded) carbons occurs farthest downfield? A) B) C) D)
E)
15. Which compound below would give rise to 4 signals in the C-13 NMR spectrum?
A) B) C) D) E)
IV III More than one of the above. II I
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Page 9 of 19 16. Which of the molecules below is most likely to have given the following 1H NMR spectrum? 6
3
3
2
3
2 PPM
A) B) C) D) E)
Version 1
1
0
Page 10 of 19 17. Which of the molecules below is most likely to have given the following 1H NMR spectrum? There is also a characteristic IR stretch near 1700 cm-1 and a characteristic peak in the 13C-NMR at 170 ppm.
3
3
22
8
7
2
6
5
4 PPM
A)
B)
C)
D)
E)
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3
3 2
2
1
0
Page 11 of 19 18. Which of the molecules below is most likely to have given the following 1H NMR spectrum? 6
3 2
2
2
1
2
1 PPM
A) B) C)
D)
E)
19. The mass spectra of alkyl bromides and chlorides are characterized by an unusually intense __________. A) parent peak B) M+• +2 peak C) base peak D) M+• +1 peak E) None of these 20. A prominent (M+• -18) peak suggests that the compound might be: A) Ether B) Alkane C) Ketone D) Primary amine E) Alcohol Version 1
0
Page 12 of 19
21. The data below from the molecular ion region of the mass spectrum of a halogencontaining compound are consistent with the presence of what halogen(s) in the original compound? Intensity M+ • 51.0 M+• +2 100.0 M+• +4 49.0 A) Two Br B) Two Cl C) One Cl D) One Br and one Cl E) One Br
22. What is the molecular formula of this compound? m/z Intensity + 78 M • 10.00 79 1 80 3.3 81 0.3 A) C6H9 B) C3H7Cl C) C6H6 D) C3H5Cl E) C6H8 23. The correct IUPAC name for:
A) B) C) D) E)
4-Methyl-1-penten-4-ol 2-Methyl-4-penten-2-ol 4-Penten-2-methyl-2-ol 4-Hydroxy-4-methyl-1-pentene 4-Methyl-1-penten-2-ol
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Page 16 of 19 Part B: Short Answer (40 marks) 1. In boxes a and b below, sketch the 1H NMR spectra that would arise from each of the following disubstituted benzenes. In addition to positioning the signals in the appropriate chemical shift regions, include a chemical structure, peak labels, integration values and splitting patterns for each chemically different 1H in your sketch. Please draw each peak as a line; do not draw a baseline. See below for an example (1H NMR sketch of propane). Example: Propane CH3 A 6 H, t
CH2 B 2 H, q
8
6
δ (ppm)
4
2
a. ortho-iodochlorobenzene (7 marks)
0
1 – structure
HA HD 1 H, d 1 H, d HB 1 H, t
3 – sketch (general order of multiplets, in aromatic reagion, splitting patterns) HC 1 H, t
8
6
3 – peak labels, integration
δ (ppm)
4
2
0
4
2
0
b. meta-iodochlorobenzene (7 marks) HA 1 H, s
HB HD 1 H, d 1 H, d HC 1 H, t
8
6
δ (ppm)
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Page 17 of 19 2. Assign all the peaks in the following 1H spectrum of vinyl acetate. Draw a tree (pitchfork) diagram of each doublet of doublets in the space below. (10 marks)
CH3 A
δ (ppm): 7.28, 1H, doublet of doublets, J = 14 Hz, 8 Hz 4.88, 1H, doublet of doublets, J = 14 Hz, 2 Hz 4.56, 1H, doublet of doublets, J = 8 Hz, 2 Hz 2.13, 3H, singlet HB
HD
HC
4 – peak assignment 6 – tree diagrams (2 each, 1 for tree structure, 1 for labeling all J values)
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Page 18 of 19 3. The IR, 1H and 13C NMR spectra are shown for a molecule with formula C8H9NO2. Label all of the NMR (and relevant IR) peaks. Propose a structure. (8 marks) 3 Ar
CH2-O C-H
Ar
C=O
N-H
o-Ph m-Ph
p-Ph
1
H NMR ZOOM (6.0 – 7.3 ppm) NH2
1 – IR 2 –C-13 labels 3 – H-1 labels 2 – final structure
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CH2-O
Page 19 of 19 4. The IR, 1H and 13C NMR spectra are shown for a molecule with formula C14H12O2. Label all of the NMR (and relevant IR) peaks. Propose a structure. (8 marks) Ar CB
Ar
CH2-O CH=O C-H
C-H (COH)
Ar CA CH=O
Ar-CH2-O
HA
1
H NMR ZOOM (7.0 – 8.0 ppm)
HB
other Ph mess CDCl3
1 – IR 2 –C-13 labels 3 – H-1 labels 2 – final structure
Version 1
MCGILL UNIVERSITY FACULTY OF SCIENCE DEPARTMENT OF CHEMISTRY
Midterm CHEMISTRY 222/234 Friday July 19th, 2013 Lea 219 6:00 – 9:00 pm
____________________________________________________________________________ LAST NAME FIRST NAME STUDENT NUMBER Time 6:00 – 9:00 pm
EXAMINERS: Professor Laura Pavelka INSTRUCTIONS: 1.
Fill in your full name and student ID number on the scantron sheet provided.
2.
Answer all multiple choice (Part 1) questions on the scantron sheet provided and answer all of the short answer (Part 2) questions in the exam booklet.
3.
Fill in the appropriate circles (darkly) on the scantron for youranswers to the multiple choice questionss only when you are sure of your response. Pens or pencils are ok.
4.
Put your name on the first page of the exam booklet and hand it in along with the scantron sheet at the end of the exam. There must be an answer sheet and an exam for each student.
5.
A periodic table, IR frequency charts, and NMR chemical shift range charts are provided as the end of the exam booklet.
6.
Molecular model kits are permitted and, for students who use English as a second language, dictionaries are permitted.
7.
THE EXAMINATION SECURITY MONITOR PROGRAM DETECTS PAIRS OF STUDENTS WITH UNUSUALLY SIMILAR ANSWER PATTERNS ON MULTIPLE-CHOICE EXAMS. DATA GENERATED BY THIS PROGRAM CAN BE USED AS ADMISSIBLE EVIDENCE, EITHER TO INITIATE OR CORRROBORATE AN INVESTIGATION OR CHARGE OF CHEATING UNDER SECTION 16 OF THE CODE OF STUDENT CONDUCT AND DISCIPLINARY PROCEDURES.
Version 1
Page 2 of 19 Part A: Multiple Choice (30 questions – 2 marks each) 1. The strongest of the intermolecular forces is which of the following? A) Dipole-dipole B) Dispersion forces C) Hydrogen bonds D) Ion-dipole E) Cation-anion
2. For the following reaction, what significant change(s) would be expected in the IR spectrum of the ether compared to that of the starting material (alcohol), ignoring any CH absorptions?
A) A peak around 2150 cm-1 would disappear and a new peak around 3300 cm-1 would appear. B) A peak around 3300 cm-1 would disappear. C) No change would be observed. D) A peak around 3300 cm-1 would disappear and a new peak around 1710 cm-1 would appear. E) None of these
3. The IR spectrum of which type of compound will not show evidence of hydrogen bonding? A) Phenol B) Carboxylic acid C) Primary amine D) Alcohol E) Aldehyde
Version 1
Page 3 of 19 4. For the functional group on the following molecule, what characteristic IR absorption would be expected, ignoring C-H absorptions?
A) B) C) D) E)
A peak around 1650 cm-1 A peak around 2250 cm-1 A peak around 3300 cm-1 A peak around 1700 cm-1 None of these
5. Which molecule would have a dipole moment greater than zero? A) H2O B) CO2 C) CCl4 D) BCl3 E) BeCl2
Version 1
Page 4 of 19 6. What is the most likely molecule that would give rise to the following IR spectrum?
A)
B)
C)
D)
Version 1
Page 5 of 19 7. What is the most likely molecule that would give rise to the following IR spectrum?
A)
B)
C) D)
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Page 6 of 19 8. What is the most likely molecule that would give rise to the following IR spectrum?
A) B) C) D)
9. For the following compound, how many different signals would you expect to see in the 1 H NMR spectrum?
A) B) C) D) E)
5 3 2 6 4
Version 1
Page 7 of 19 10. For the following compound, how many different signals would you expect to see in the 1 H NMR spectrum?
A) B) C) D) E)
5 7 8 6 4
11. In NMR terminology, what classification do we give HA and HB?
A) B) C) D) E)
enantiotopic protons. isomeric protons. vicinal protons. homotopic protons. diastereotopic protons.
12. The 1H NMR signal for which of the indicated protons occurs farthest downfield?
A) B) C) D) E)
HE HD HA HC HB
Version 1
Page 8 of 19 13. In NMR terminology, what classification do we give HA and HB?
A) B) C) D) E)
Homotopic Heterotopic Enantiotopic Diastereotopic Identical
14. The 13C NMR signal for which of the indicated (bolded) carbons occurs farthest downfield? A) B) C) D)
E)
15. Which compound below would give rise to 4 signals in the C-13 NMR spectrum?
A) B) C) D) E)
IV III More than one of the above. II I
Version 1
Page 9 of 19 16. Which of the molecules below is most likely to have given the following 1H NMR spectrum? 6
3
3
2
3
2 PPM
A) B) C) D) E)
Version 1
1
0
Page 10 of 19 17. Which of the molecules below is most likely to have given the following 1H NMR spectrum? There is also a characteristic IR stretch near 1700 cm-1 and a characteristic peak in the 13C-NMR at 170 ppm.
3
3
22
8
7
2
6
5
4 PPM
A)
B)
C)
D)
E)
Version 1
3
3 2
2
1
0
Page 11 of 19 18. Which of the molecules below is most likely to have given the following 1H NMR spectrum? 6
3 2
2
2
1
2
1 PPM
A) B) C)
D)
E)
19. The mass spectra of alkyl bromides and chlorides are characterized by an unusually intense __________. A) parent peak B) M+• +2 peak C) base peak D) M+• +1 peak E) None of these 20. A prominent (M+• -18) peak suggests that the compound might be: A) Ether B) Alkane C) Ketone D) Primary amine E) Alcohol Version 1
0
Page 12 of 19
21. The data below from the molecular ion region of the mass spectrum of a halogencontaining compound are consistent with the presence of what halogen(s) in the original compound? Intensity M+ • 51.0 M+• +2 100.0 M+• +4 49.0 A) Two Br B) Two Cl C) One Cl D) One Br and one Cl E) One Br
22. What is the molecular formula of this compound? m/z Intensity + 78 M • 10.00 79 1 80 3.3 81 0.3 A) C6H9 B) C3H7Cl C) C6H6 D) C3H5Cl E) C6H8 23. The correct IUPAC name for:
A) B) C) D) E)
4-Methyl-1-penten-4-ol 2-Methyl-4-penten-2-ol 4-Penten-2-methyl-2-ol 4-Hydroxy-4-methyl-1-pentene 4-Methyl-1-penten-2-ol
Version 1
Page 16 of 19 Part B: Short Answer (40 marks) 1. In boxes a and b below, sketch the 1H NMR spectra that would arise from each of the following disubstituted benzenes. In addition to positioning the signals in the appropriate chemical shift regions, include a chemical structure, peak labels, integration values and splitting patterns for each chemically different 1H in your sketch. Please draw each peak as a line; do not draw a baseline. See below for an example (1H NMR sketch of propane). Example: Propane CH3 A 6 H, t
CH2 B 2 H, q
8
6
δ (ppm)
4
2
a. ortho-iodochlorobenzene (7 marks)
0
1 – structure
HA HD 1 H, d 1 H, d HB 1 H, t
3 – sketch (general order of multiplets, in aromatic reagion, splitting patterns) HC 1 H, t
8
6
3 – peak labels, integration
δ (ppm)
4
2
0
4
2
0
b. meta-iodochlorobenzene (7 marks) HA 1 H, s
HB HD 1 H, d 1 H, d HC 1 H, t
8
6
δ (ppm)
Version 1
Page 17 of 19 2. Assign all the peaks in the following 1H spectrum of vinyl acetate. Draw a tree (pitchfork) diagram of each doublet of doublets in the space below. (10 marks)
CH3 A
δ (ppm): 7.28, 1H, doublet of doublets, J = 14 Hz, 8 Hz 4.88, 1H, doublet of doublets, J = 14 Hz, 2 Hz 4.56, 1H, doublet of doublets, J = 8 Hz, 2 Hz 2.13, 3H, singlet HB
HD
HC
4 – peak assignment 6 – tree diagrams (2 each, 1 for tree structure, 1 for labeling all J values)
Version 1
Page 18 of 19 3. The IR, 1H and 13C NMR spectra are shown for a molecule with formula C8H9NO2. Label all of the NMR (and relevant IR) peaks. Propose a structure. (8 marks) 3 Ar
CH2-O C-H
Ar
C=O
N-H
o-Ph m-Ph
p-Ph
1
H NMR ZOOM (6.0 – 7.3 ppm) NH2
1 – IR 2 –C-13 labels 3 – H-1 labels 2 – final structure
Version 1
CH2-O
Page 19 of 19 4. The IR, 1H and 13C NMR spectra are shown for a molecule with formula C14H12O2. Label all of the NMR (and relevant IR) peaks. Propose a structure. (8 marks) Ar CB
Ar
CH2-O CH=O C-H
C-H (COH)
Ar CA CH=O
Ar-CH2-O
HA
1
H NMR ZOOM (7.0 – 8.0 ppm)
HB
other Ph mess CDCl3
1 – IR 2 –C-13 labels 3 – H-1 labels 2 – final structure
Version 1
