Practice Exam 1
Note: This exam is comprised of questions from Chem 25a exams from Summer 2021. You can
expect a similar length and mixture of question styles (MC, fill in, explanation, etc.) on your
exam.
1. CellCept (shown below) is a medication prescribed to patients who have
undergone heart, liver, or kidney transplants to help prevent their immune
system from rejecting the donor organ. The following questions all refer to the
structure of CellCept which is repeated in each question.
a. Circle and label 3 functional groups in CellCept.
b. Select all of the descriptors that are applicable to the alkene present in cellcept.
i. E alkene
ii. Z alkene
iii. Monosubstituted alkene
iv. Disubstituted alkene
v. Trisubstituted alkene
vi. Tetrasubstituted alkene
vii. Internal alkene
viii. Terminal alkene
c. What is the degree of unsaturation (aka degree/index of hydrogen deficiency) of
CellCept?
d. How many quaternary carbons are in CellCept?
e. What is the molecular geometry of the carbon labeled A in CellCept?
f. What is the hybridization of the carbon labeled B in CellCept?
2. How many carbon atoms are in the principle chain of the molecule below?
3. What is the name of the following molecule?
4. Which of the following best describes the molecule below?
a. Contains at least one polar bond and has an overall molecular dipole.
b. Contains at least one polar bond but does not have an overall molecular dipole.
c. Does not contain any polar bonds and therefore does not have an overall
molecular dipole.
5. What is the degree of unsaturation for a molecule with the molecular formula
C9H9BrO2?
6. The following questions are all in relation to the three molecules shown below.
a. What is the relationship between Molecule A & Molecule C?
i. Unrelated
ii. Conformational isomers
iii. Enantiomers
iv. Diastereomers
v. Constitutional (structural) isomers
b. Label each asymmetric carbon in Molecule B as R or S.
7. Which of the following statements is false?
a. Diastereomers cannot be superimposed on each other.
b. Not all stereoisomers contain asymmetric carbons.
c. Meso compounds contain asymmetric carbons but are achiral molecules.
d. Molecules with asymmetric carbons do not have free rotation around single
bonds.
8. Which of the following chair conformations shows the most stable chair for the
molecule below?
9. Which of the following is the chair flipped conformation of the molecule below?
10. a. Draw the following Newman projection as the corresponding skeletal structure. Be
sure to use wedges and dashes to indicate the 3-dimensional shape of the molecule.
b. Redraw the Newman projection as the most stable conformation of the molecule.
c. What terminology would you use to describe the orientation of the molecule in part
b?
11. Label each of the following molecules as aromatic, non-aromatic or antiaromatic.
12. The two molecules below are structurally similar to each other. Using resonance
structures, explain which on is more stable.
13. The following molecules all have the same molecular formula, but different boiling
points. Rank the compounds from highest boiling to lowest boiling and explain why you
ranked them in that order.
