Final Exam - Napa Valley College Pages 240/4 - Finals Ex… · Chem 240 Name_____ Final Exam December 18, 2000 CLOSED BOOK EXAM - No books or notes allowed. All work must be shown

Final Exam

Comprehensive Exam

Chem 240 Name___________________

Final Exam December 18, 2000

CLOSED BOOK EXAM - No books or notes allowed. All work must be shown for full

credit. You may use a calculator.

Question Credit Question Credit

1(18 ) 7(24)

2(10) 8(36)

3(20) 9(12)

4(12) 10(8)

5(16) 11(15)

6(9) 12(20)

TOTAL TOTAL

I want my final to count for 300 pts. ______________________________

(This will drop your lowest exam) Signature

1) Please name or draw the structure of the following compounds.

2) Please draw the most stable form of trans-1,3-dimethyl cyclohexane.

3) Please draw the complete mechanism of the acid catalyzed addition of ethanol to 3-

methyl butene and then draw the reaction diagram.

4) Please draw the product of the Saytzeff elimination of HBr from the following

compound. Two products are possible, but only one is made. Show how both could be

made and EXPLAIN which one is possible and why.

5) Circle the type of reaction occuring in each of the following reactions. If more than

one reaction type occurs label the major and minor product.

6) There are three forces that hold liquids together. Please explain how each of these

contributes to the overall bonding in liquids and order them according to relative strength.

7) Label each of the following compounds R,S.

A B C D

7b) Which are enantiomers and diasteromers, and which compound (if any) is meso?

C

C

C

C

C

C

C

C

Cl

Cl

Cl ClHH

H H

CH3

CH3

CH3

CH3H

H H HCl Cl

Cl

Cl

CH3

CH3 CH3 CH3

8) Please give the product for each of the following reactions.

1)

2)

C C

C

CH3

C C C C

C

Cl

H Cl

Per ox ide

K Mn O 4

CH3

PBA

C C C

C

ClK I

C C C C

Cl

CH3

H 2O , K O H

EtO H , Hea t

BH 3, H 2O 2

H 2O , K O H

H 2SO 4 , H 2O

Mg

H 2O

OHP / I 2

OsO 4

H 2 O 2 , H 2 O

C C

C

C

CHg ( O Ac) 2

CH 3 O H , NaBH 4

C C OHH 2 SO 4 , Hea t

9a) Please show all the steps in the free radical chlorination of 2 methyl butane. It is

important for the chlorine to become attached to the proper carbon so be careful of which

carbon you choose to halogenate.

9b) Please give the ratio of products made in the free radical chlorination of 1,1 dimethyl

cyclohexane.

10) Please draw the Lewis structure of C4H4O4

11) Please give all the steps in the Fisher ester synthesis of ethyl acetate.

12) Starting with alkanes of two carbons or less synthesize any two of the following;

Chem 240 Name__Answer Key ______

Final Exam December 18, 2000

CLOSED BOOK EXAM - No books or notes allowed. All work must be shown for full

credit. You may use a calculator.

Question Credit Question Credit

1(18 ) 7(24)

2(10) 8(36)

3(20) 9(12)

4(12) 10(8)

5(16) 11(15)

6(9) 12(20)

TOTAL TOTAL

I want my final to count for 300 pts. ______________________________

(This will drop your lowest exam) Signature

1) Please name or draw the structure of the following compounds.

E 3-chloro-2-iodo-2-propene-1-ol

1R,2R,3S-4-chloro-2-bromo-cyclopentanol

3-ethyl-4-methyl-heptane 3R,4R-4-chloro-3-pentanol

E,Z-3-bromo-4-methyl-2,4-hexadiene cyclopentyl(sec-butyl) ether

2) Please draw the most stable form of trans-1,3-dimethyl cyclohexane.

3) Please draw the complete mechanism of the acid catalyzed addition of ethanol to 3-

methyl butene and then draw the reaction diagram.

4) Please draw the product of the Saytzeff elimination of HBr from the following

compound. Two products are possible, but only one is made. Show how both could be

made and EXPLAIN which one is possible and why.

5) Circle the type of reaction occuring in each of the following reactions. If more than

one reaction type occurs label the major and minor product.

6) There are three forces that hold liquids together. Please explain how each of these

contributes to the overall bonding in liquids and order them according to relative strength.

1. Hydrogen Bonding – it is the strongest bond. It is a sharing of H’s in compound

with OH or NH bonds.

2. Dipole-Dipole – the second strongest bond. It is the attraction between + and – in

molecules with dipoles.

3. Diserson/London Forces – the weakest of the forces. Transient dipoles are made

when molecules bump into each other, and these weak dipoles attract one another.

7) Label each of the following compounds R,S.

2S, 3R 2R, 3S 2R, 3R 2S, 3R

A B C D

7b) Which are enantiomers and diasteromers, and which compound (if any) is meso?

A B, and D are the same compound – these are all meso so there are no enantiomers. C

and (A,B,D) are diastereomers.

C

C

C

C

C

C

C

C

Cl

Cl

Cl ClHH

H H

CH3

CH3

CH3

CH3H

H H HCl Cl

Cl

Cl

CH3

CH3 CH3 CH3

8) Please give the product for each of the following reactions.

9a) Please show all the steps in the free radical chlorination of 2 methyl butane. It is

important for the chlorine to become attached to the proper carbon so be careful of which

carbon you choose to halogenate.

9b) Please give the ratio of products made in the free radical chlorination of 1,1 dimethyl

cyclohexane.

CH3

CH3

X

100-X=

6

10

1

3.5x1

o

2o

35X = 600 - 6X

41X = 600

X = 14.63%

10) Please draw the Lewis structure of C4H4O4

11) Please give all the steps in the Fisher ester synthesis of ethyl acetate.

12) Starting with alkanes of two carbons or less synthesize any two of the following;