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Practice Questions for Exam 1

CH2230 Fall 2018

Clemson University

1. Assuming all the C, N, and O atoms have a full

octet, which atom(s) in the structure of the body-

building supplement creatine, shown below, must

have a formal charge?

A. 1 and 2 C. 1 and 3

B. 2 and 4 D. 1, 3, and 5

E. 2 and 5

2. How many atoms in the molecule shown are sp3

hybridized?

A. 0

B. 1

C. 2

D. 3

E. 4

3. Which of the following is the correct condensed

representation of the structure of isooctane, the

definition of 100 octane in gasoline whose

skeletal/bond-line structure is shown?

A. (CH3)3CCH2CH(CH3)2

B. (CH3)4CCH2CH2(CH3)

C. (CH3)3CH2CCH(CH3)2

D. (CH2)2CCH2CH(CH3)2

E. (CH4)4CH2CCH(CH3)2

4. Which functional groups are present in the

structure of aspartame (artificial sweetener in the

blue packets) (not all are necessarily listed in the

answer)?

A. Amine, amide, arene, aldehyde

B. Arene, alcohol, ester, amine

C. Alcohol, acid chloride, alkyne, amide

D. Alkyne, arene, ketone, alkene

E. None of the above are correct

5. Which of the following compounds contains an

amine functional group?

A. I

B. II

C. III

D. IV

E. None of these

6. How many total atoms are connected to the

indicated carbon atom?

A. none

B. one

C. two

D. three

E. four

7. How many total atoms are connected to the

indicated carbon atom?

A. none

B. one

C. two

D. three

E. four

8. In the following structure, all of the nonbonding

electrons are shown, but the formal charges (F.C.)

are missing:

Which is true of this molecular representation?

A. An atom with a F.C. of 0 is closest to the

viewer

Use these practice questions to help in your preparation for the exam. Do not memorize these questions as the questions on your exam will be different.

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B. An atom with a F.C. of +1 is closest to the

viewer

C. An atom with a F.C. of –1 is closest to the

viewer

D. An atom with a F.C. of –2 is closest to the

viewer

E. None of these

9. What is the formal charge on the nitrogen atom in

the following compound?

A. –1

B. –2

C. +1

D. +2

E. 0

10. Which of the following compounds have +1 as a

formal charge on the nitrogen atom?

A. I

B. II

C. III

D. IV

E. Both I and II

11. How many lone pairs of electrons are on the

oxygen atom?

A. one

B. two

C. three

D. four

E. none

12. In the progesterone molecule shown, how many

hydrogens are cis to the two methyl groups?

A. 1

B. 3

C. 5

D. 9

E. 11

13. Which of the following statements, if any, is

incorrect?

A. NH3 can act as a Brønsted-Lowry acid and

base

B. CH3NH2 can act as a Lewis acid and base

C. BF3 is a Lewis base

D. AlCl3 is a Lewis acid

14. A Brønsted-Lowry acid is a:

A. proton acceptor

B. proton donor

C. electron donor

D. electron acceptor

15. In the following reaction, which reactant functions

as a base?

A. I

B. II

C. III

D. IV

E. none of the above

16. Identify the conjugate acid of the reactant base in

the following reaction.

A. I

B. II

C. III

D. IV

E. none of the above

17. The following compound is best classified as a_

A. Brønsted-Lowry acid

B. Lewis acid

C. Brønsted-Lowry base

D. Lewis base

E. Both C & D

18. Which will have the lowest pKa value:

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19. Which of the following molecules has the lowest

boiling point?

A. 2-methylpentane

B. 2-methylpropane

C. 2-methylbutane

D. pentane

E. butane

20. Which of the following is a Newman projection for

the following compound as viewed down the

indicated bond in the conformation shown?

A. I

B. II

C. III

D. IV

21. Which of the following bases is the strongest?

22. Which of the following is a wedge and dash structure

for the following Newman projection?

A. I

B. II

C. III

D. IV

23. Which of the following Newman Projections

represents the most stable conformation. Note: this

is not a straightforward question, think about it!

A.

B.

C.

D.

24. Which of the following is a Newman projection of a

staggered conformation for ethane?

A. I

B. II

C. III

D. IV

25. Name the other molecules in the Newman

projections of the previous question, and indicate

eclipsed or staggered for each.

26. Which of the following is a gauche

conformation for butane?

A. I

B. II

C. III

D. IV

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27. In the previous question, all were conformations of

butane sited along the ______ bond, and conformation

____ is the least stable.

28.Which of the following is an antiperiplanar (“anti”)

conformation for butane?

A. I

B. II

C. III

D. IV

29. Which of the following is the highest energy

conformer of 2-methylbutane looking down the

C3-C2 bond?

A. I

B. II

C. III

D. IV

30. Consider the two chair conformations for cis-1,2-

dimethylcyclohexane. Which is most stable?

A. The conformation with two equatorial methyls

B. The conformation with two axial methyls

C. They are equal in stability because one methyl

is equatorial and the other is axial in each

conformation.

31. Which of the following is the lowest energy

conformer of the most stable isomer of 1,2,4-

trimethylcyclohexane?

A. I

B. II

C. III

D. IV

32. Consider the structure of progesterone shown.

Which statement is most accurate?

A. The molecule contains trans-decalin, one

ketone, and one aldehyde group.

B. The molecule contains cis-decalin, one ketone,

and one aldehyde group. C. The molecule contains trans-decalin and two

ketone groups. D. The molecule contains cis-decalin and two

ketone groups.

33. Which of the following statements, if any, is not

correct about the following four molecules?

A. All would have a methyl group axial most of

the time

B. One would have a methyl group axial all of the

time

C. At least two of the molecules would have a

methyl group axial close to or 100% of the

time

D. At least two of the molecules are shown in

their most stable conformation

E. All of the statements above are correct.

34. Which of the following illustrates an axial OH?

A. I

B. II

C. III

D. IV

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35. Which is the least stable chair conformer of the

following compound?

A. I

B. II

C. III

D. IV

36. Which of the following is the lowest energy

conformer of the most stable isomer of 1,4-

diethylcyclohexane?

A. I

B. II

C. III

D. IV

37. Which of the following is the lowest energy chair

conformation of the following cyclohexane?

A. I

B. II

C. III

D. IV

38. Which isomer has a conformation that is more

stable?

A. I

B. II

C. Equal

39. Which isomer has a conformation that is more

stable?

A. I

B. II

C. Equal

40. HA has a pKa of 6, while HB has a pKa of 11. The

equilibrium that results upon mixing HA with NaB

is this

H−A + B− ⇌ A− + H−B

Which statement is most accurate regarding this

reaction?

A. The reaction favors the left side, and sodium

ions gained an electron in an explosive

reduction.

B. The reaction favors the right side, and sodium

ions gained an electron in an explosive

reduction.

C. The reaction favors the left side, and sodium

ions were omitted because they are spectator

ions.

D. The reaction favors the right side, and sodium

ions were omitted because they are spectator

ions.

Consider this compound for the next 11 questions.

41. Number of hydrogens ________

42. formula ___________

43. # sigma (σ) bonds _____

44. # pi (π) bonds _____

45. # lone pairs of electrons _____

46. Add formal charges

47. How many carbon atoms are sp3 hybridized? ___

48. Which other atoms are sp3 hybridized? ___

49. How many carbon atoms are sp2 hybridized? ___

50. What other atoms are sp2 hybridized? ___

51. On which atom is the most acidic proton? ___

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52. Consider pKa values for this question. (You’ll have

to go look them up if you have not memorized any

yet). Which of these will exist predominantly in the

deprotonated state at a pH of 10.5?

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The last page of Exam 1 will have a Periodic Table. ______________________________________________________________________________________________

USEFUL INFORMATION: _______________________________________________________________________________________

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Question

number

answer

1 E

2 D

3 A

4 E

5 D

6 D

7 D

8 B

9 C

10 D

11 C

12 D

13 C

14 B

15 B

16 D

17 E

18 B

19 B

20 B

21 D

22 B

23 A

24 A

25 II ethane, eclipsed

III propane, staggered

IV propane, eclipsed

26 C

27 C2-C3, IV

28 A

29 D

30 C

31 C

32 C

33 E

34 B

35 C

36 B

37 D

38 B

39 B

40 D

41 22

42 C12H22NO

43 36

44 2

45 2

46 + on N

47 9

48 N

59 3

50 O

51 N

52 1 and 4