1

Chem 2300

Exam 1

September 26, 2014

Name: (Please print)

(First) (Last)

Last 4 digits of A

Number

Score

I. Multiple Choice

( /30)

/90

II

/5

III

/5

Total score

/100

Note: Periodic table and pKa Values are on page 14.

2

I. Multiple choice questions. (3 points each). Please put your answers on Scantron sheet. Your

score will be graded based only on your answers from Scantron sheet.

1. Which is the electronic configuration that describes Na+?

(a) 1S2, 2S

2

(b) 1S2, 2S

2, 2P

6

(c) 1S2, 2S

2, 2P

6, 3S

2

(d) 1S2, 2S

2, 2P

6, 3S

2, 3P

6

(e) None of the above

2. Which of the following elements or ions is the least stable?

(a) Li+

(b) F-

(c) Ar

(d) Na

(e) Cl-

3. In the figure on the right, which represent the correct tendency of electronegativity?

(a) I, IV, VI

(b) II, III, IV

(c) I, III, V

(d) II, IV, V

(e) None of the above

4. What is the correct Lewis structure for the following compound?

CH2CHCOCH3

3

5. What is the skeletal structure for the following compound?

CH3CH2CH2CH2CH(CH3)NH(CH3)

6. What orbital does the lone-pair electrons on the nitrogen atom of the following compound

occupy?

(a) SP3

(b) SP2

(c) SP

(d) P

(e) None of the above

7. What orbital does the lone-pair electrons on the oxygen atom pointed by arrow "a" of the

following compound occupy?

(a) SP3

(b) SP2

(c) SP

(d) P

(e) None of the above

4

8. What are the correct Lewis structures for the following compounds?

(a) I, III, V, VI, VII, IX

(b) I, III, IV, V, VII, IX

(c) I, II, VI, VII, VIII, IX

(d) I, III, V, VII, IX

(e) None of the above

9. Acetaminophen, the active ingredient in Tylenol, is a commonly used drug for reducing pain,

reducing fever, and relieving the symptoms of allergies, cold, cough, and flu. Using the VSEPR

model, predict which atoms have sp3 hybridization. (Note: lone-pair electrons are not shown)

(a) Those pointed by arrows “a”, “c” and “f”.

(b) Those pointed by arrows “a”, “c”, “d” and “e”.

(c) Those pointed by arrows “b”, “d” and “e”.

(d) Those pointed by arrows “b”, “d” and “f”.

(e) None of the above

5

10. Organic compounds that have more polarized functional group, such as C=O, OH or NH2,

tend to interact more strongly with water and become more soluble in water. Which of the

following vitamin would be the most soluble in water (water soluble)?

11. Which compound(s) below are Lewis acid?

(a) I, II, III

(b) I, III, IV

(c) I, II, IV

(d) III, IV, V

(e) None of the above

12. Arrange the following compounds in order of their acidity (from the most acidic to the least).

I II III IV

CH3CH2OH CF3CO2H CCl3CO2H CH3CO2H

(a) I>III>II>IV

(b) II>III>I>IV

(c) II>III>IV>I

(d) III>II>IV>I

(e) None of the above

6

13. What is the IUPAC name for the following compound?

(a) 4-methyl-5-ethylheptane

(b) 2-propyl-3-ethylpentane

(c) 3-methyl-2-ethylheptane

(d) 3-ethyl-4-methylheptane

(e) None of the above

14. What is the IUPAC name for the following compound?

(a) 2,4-dimethyl-1-isopropylcyclopentane

(b) 1,3-dimethyl-4-isopropylcyclopentane

(c) 1-isopropyl-2,4-dimethylcyclopentane

(d) 1-isopropyl-3,5-dimethylcyclopentane

(e) None of the above

15. How many tertiary (3°) carbons does cholesterol have? (Note: sp2 hybridized carbon and

carbon with heteroatom attached (ex. O, N, and halogens) cannot be classified as 1°, 2°, 3° or 4°)

(a) 6

(b) 7

(c) 8

(d) 9

(e) 10

cholesterol

16. What is the systematic name for the following compound?

(a) 4-ethyl-5-fluorooctane

(b) 5-fluro-4-ethyloctane

(c) 4-fluoro-5-ethyloctane

(d) 5-ethyl-4-fluorooctane

(e) None of the above

17. Which of the following compound is the most soluble in water (water soluble)?

7

18. Which compounds belong to primary (1º) alkyl alcohols?

(a) IV, VI, VII

(b) II, III, V

(c) IV, VII, VIII

(d) II, III, VII

(e) None of the above

19. Which compounds belong to primary (1º) alkyl halides?

(a) I, III, V, VIII

(b) II, III, V, VIII

(c) III, VII, VIII

(d) II, III, VII, VIII

(e) None of the above

8

20. Which of the following is not a structure isomer when compared to other molecules?

21. Which of the following compounds belong to 3º amine?

NH

CH3

NH2

CH3CH2CH2NH2 CH3CH2CH2CH2CH2N(CH3)2

NH

N

N

I II IIIIV

V VIVII

VIII

NH2

NH2

NH2

IX X XI XII

NH2

NH2

NH2

(a) VI, VII,VIII

(b) II, III, VI

(c) II, IV, XI

(d) VI, VII

(e) None of the above

9

22. Which of the following compounds when exist in pure form can have hydrogen bond?

OH

OOH

O O

I II III IV V

(a) I, II, III

(b) II, III

(c) I, IV

(d) I, III, IV

(e) None of the above

23. Which of the following molecules is the least stable?

(a) I

(b) II

(c) III

(d) IV

(e) None of the above

24. Which of the following molecules represents trans isomer?

I II III IVCH3

CH3

CH3

CH3CH3

CH3

CH3

CH3

(a) I, II

(b) II, III

(c) III, IV

(d) II, III, IV

(e) None of the above

10

25. What is the order of stability for the following conformational isomers of n-butane (most to

least)?

(a) I>II>III>IV

(b) I>V>II>III

(c) I>V>III>IV

(d) I>II>IV>III

(e) None of the above

26. Which of the following compound is the least stable (most reactive)?

27. What is the systematic name for the following compound?

(a) 1-ethoxycyclohexanol

(b) 2-ethoxycyclohexanol

(c) 1-ethyloxycyclohexanol

(d) 2-ethyloxycyclohexanol

(e) None of the above

28. What is the systematic name for the following compound?

(a) cis-4-methyl-3-hexene

(b) trans-3-methyl-3-hexene

(c) (Z)-3-methyl-3-hexene

(d) (E)-3-methyl-3-hexene

(e) None of the above

H

H3C

H

CH3

HH

H

HH3C

H

H

CH3

CH3

HH

H

H

H

H

CH3H3C

H

H

CH3

H

HH3C

H

H3C

H

I IIIII IV V

11

29. Which of the following compounds have Z configuration (carbon-carbon double bond)?

Cl

I

Br Br

IIIII

HOBr

Cl

IV

O

(a) I, III, IV

(b) I, II, III

(c) I, IV

(d) I, II, III, IV

(e) None of the above

30. Arrange these molecules in order of stability (most to least).?

(a) I>II>III>IV

(b) I>II=III>IV

(c) III>I>II>IV

(d) II=III>I>IV

(e) I>III>II>IV

Continue to the Next Page

12

II. Provide the Lewis structures for the following compounds in designated cells. Follow the

instruction for each individual formula as required. Assign formal charges as appropriate. (5

points)

A: HNO3 as nitric acid

B: H2SO4 as sulfuric acid C: CH3CO2H as acetic acid

D: O3 as ozone

E: HO2CCH2COH(CO2H)CH2CO2H as citric acid (a compound

with three carboxylic acids)

Continue to the Next Page

13

III. A general structure of a hexopyranose (a sugar) in cyclic hemiacetal form is listed below.

Draw the most stable chair structure for this molecule. You need to place the OH groups and

CH2OH group in the correct positions to get full points. (5 points)

Next Page: Periodic Table & pKa Values

14

pKa Values for Some organic and Inorganic Acids

Acid Formula pKa Conjugate Base

Ethane CH3CH3 51 CH3CH2-

Ammonia NH3 38 NH2-

Ethanol CH3CH2OH 15.9 CH3CH2O-

Water H2O 15.7 HO-

Methylammonium ion CH3CH2NH3+

10.64 CH3CH2NH2+

Bicarbonate ion HCO3-

10.33 CO32-

Phenol C6H5OH 9.95 C6H5O-

Ammonium ion NH4+

9.24 NH3

Carbonic acid H2CO3

6.36 HCO3-

Acetic acid CH3CO2H 4.76 CH3CO2-

Benzoic acid C6H5CO2H 4.19 C6H5CO2-

Phosphoric acid H3PO4 2.1 H2PO4-

Hydronium ion H3O+ -1.74 H2O

Sulfuric acid H2SO4 -5.2 HSO4-

Hydrogen chloride HCl -7 Cl-

Hydrogen bromide HBr -8 Br-

Hydrogen iodide HI -9 I-