CHEMISTRY 241H — ANALYTICAL METHODS
EXAM 2 - 2/5/2026
SPRING 2026 — SECTION 001 — DR. TIANI
Name (Last, First): _ Ke\j PID:
--—Instructions: S e e
1. Write your name and PID in the spaces provided above.
2. Write free response in pen, multiple-choice/select can be done in pencil.
3. Read each question carefully.
4. For multiple choice questions, do not circle choice — write letter choice in
box provided.
5. For multiple-select questions, do not circle choices — mark an X in
each appropriate box.
6. SHOW YOUR WORK with correct units and sig figs. Partial credit based
on work shown.
7. Double-check your calculations.
8. ANSWERS MUST BE PLACED IN THE BOXES or LINES (including
CORRECT UNITS and sig figs).
9. Do not leave any answers blank.
10.Read and sign the honor pledge when, and only when, you finish
taking the exam.
11.Return all pages when you complete the exam.
12.Relax. You've got this.
Honor Pledge: By signing below, I pledge that I have not violated the UNC Honor Code
by receiving or giving unauthorized assistance on this exam. If I do not sign, then I
acknowledge that I was not honorable in taking the exam and understand that it will
simply not be graded, no questions asked.
(Signature)
, . (9 points) Name the best type of liguid chromatography, of the 5 types of
chromatography we discussed in class, that would be the best choice to
separate each of the following pairs of substances.
. Separation of CHsCH2CH2CH20H and CH3CHCH20H
@Of‘\‘(\\ N
. Isolation of an enzyme that selectively binds Protein D from a sample of
blood serum. AQ&{\,\\/
. The determination of the molecular weight of a polymer that was
synthesized by a friend in a polymer synthesis lab.
2EeC
. (5 points) Species 1, 2, 3, and 4 were separated using gas
chromatography, where species 1 is the solvent. The resulting
chromatogram is shown. Which statements are true regarding
the chromatogram? Select all that apply by placing an “X” in the
box next to each of the below options.
]
Detector response
R o
J\ A . Cr\'\
2 4 6 .8 - o 12 14 1 5(\(\? Sj
Time (min)
] Species 1 has the highest distribution constant. ( lq 03
XSpecies 4 has the highest distribution constant.
7y nrs.
~]
At t=8-min;thereismore of species T imthe statiomary phdse compared
wto annninn 4.
fiAt t=8 min, there is more of species 4 in the stationary phase compared
to species 2.
:XSpemes 1 has the lowest distribution constant.
7] Species 4 has the lowest distribution constant.
EXAM 2 - 2/5/2026
SPRING 2026 — SECTION 001 — DR. TIANI
Name (Last, First): _ Ke\j PID:
--—Instructions: S e e
1. Write your name and PID in the spaces provided above.
2. Write free response in pen, multiple-choice/select can be done in pencil.
3. Read each question carefully.
4. For multiple choice questions, do not circle choice — write letter choice in
box provided.
5. For multiple-select questions, do not circle choices — mark an X in
each appropriate box.
6. SHOW YOUR WORK with correct units and sig figs. Partial credit based
on work shown.
7. Double-check your calculations.
8. ANSWERS MUST BE PLACED IN THE BOXES or LINES (including
CORRECT UNITS and sig figs).
9. Do not leave any answers blank.
10.Read and sign the honor pledge when, and only when, you finish
taking the exam.
11.Return all pages when you complete the exam.
12.Relax. You've got this.
Honor Pledge: By signing below, I pledge that I have not violated the UNC Honor Code
by receiving or giving unauthorized assistance on this exam. If I do not sign, then I
acknowledge that I was not honorable in taking the exam and understand that it will
simply not be graded, no questions asked.
(Signature)
, . (9 points) Name the best type of liguid chromatography, of the 5 types of
chromatography we discussed in class, that would be the best choice to
separate each of the following pairs of substances.
. Separation of CHsCH2CH2CH20H and CH3CHCH20H
@Of‘\‘(\\ N
. Isolation of an enzyme that selectively binds Protein D from a sample of
blood serum. AQ&{\,\\/
. The determination of the molecular weight of a polymer that was
synthesized by a friend in a polymer synthesis lab.
2EeC
. (5 points) Species 1, 2, 3, and 4 were separated using gas
chromatography, where species 1 is the solvent. The resulting
chromatogram is shown. Which statements are true regarding
the chromatogram? Select all that apply by placing an “X” in the
box next to each of the below options.
]
Detector response
R o
J\ A . Cr\'\
2 4 6 .8 - o 12 14 1 5(\(\? Sj
Time (min)
] Species 1 has the highest distribution constant. ( lq 03
XSpecies 4 has the highest distribution constant.
7y nrs.
~]
At t=8-min;thereismore of species T imthe statiomary phdse compared
wto annninn 4.
fiAt t=8 min, there is more of species 4 in the stationary phase compared
to species 2.
:XSpemes 1 has the lowest distribution constant.
7] Species 4 has the lowest distribution constant.
