CHEM 234 ORGANIC CHEMISTRY LABORATORY EXAM
CHEM 234 ORGANIC CHEMISTRY LABORATORY EXAM
name:__________________________
Student ID:__________________________
This exam is worth 100 points toward your final course grade.
I. Chemical Structures (20 pts, 2 each)
Write the chemical structures (including stereochemistry) of the compounds listed below. All of these
chemicals were used in the laboratory this semester.
a. aspirin
b. ethylacetate
c. tAcetaminophen
d. Caffine
e. common drying agents used in the lab
f. List four suitable solvents for recrystalization
measurements (no structure)
g. structure of ferrocene
h. Structure of acetyl ferrocene
i. Structure of Eugenol
j. Structure of diethyl ether
II. (10 pts, 5 each)
What is the differnece between Ferrocene and Acetyl ferrocene. If you have a mixture of the two compounds,
how do you separated them out of a mixture?
III. Reaction Mechanisms (12 pts,
Show the major organic salt formed when asprine is treated with 2M NaOH
2
IV. General Laboratory Knowledge (48 pts) - brief answers please.
1. (2 pts) Does aspirin have a higher solubility in dichloromethane or aqueous base?
2. (2 pts) Does Acetaminophen have a higher solubility in dichoromethane or ethanol? Explain Why?
3. (2 pts) What device is used in the chemical laboratory to separate two immiscible liquids of differing density
(a device you used this session)?
4. (2 pts) What is a key feature of a good recrystallization solvent?
5. (2 pts) Impure solids generally melt at (circle one) lower / higher / the same temperature as a pure solid.
6. (2 pts) Name the ways to separate two solids from each other.
3
7.
(2 pts) When distilling an ideal binary mixture of liquids through an efficient column the pot temperature
will be (circle one) higher / lower than the head temperature.
10. (2 pts) In an extraction involving dichloromethane / water, which phase will be on top?
11. (2 pts) To extract an organic material from aqueous solution, would it be better to do one extraction with
100 mL ether or 2 extractions with 50 mL each of ether?
12. (2 pts) What are two common methods of visualizing the âspotsâ of molecules on TLC plates?
13. (2 pts) If a polar compound gives an Rf value of 0.5 using elution with 1:1 hexane : ethylacetate, what will
happen to its Rf value if the amount of ethylacetate is increased?
14. (2 pts) What is the most common stationary chromatography phases for TLC or column chromatography?
15. (2 pts) Name four functional groups that you can easily identify using IR spectrospopy
4
18. (2 pts) How can one distinguish an alcohol from an ester by IR spectroscopy?
20. (6 pts) List any problems with the following fractional distallation set up.
5
name:__________________________
Student ID:__________________________
This exam is worth 100 points toward your final course grade.
I. Chemical Structures (20 pts, 2 each)
Write the chemical structures (including stereochemistry) of the compounds listed below. All of these
chemicals were used in the laboratory this semester.
a. aspirin
b. ethylacetate
c. tAcetaminophen
d. Caffine
e. common drying agents used in the lab
f. List four suitable solvents for recrystalization
measurements (no structure)
g. structure of ferrocene
h. Structure of acetyl ferrocene
i. Structure of Eugenol
j. Structure of diethyl ether
II. (10 pts, 5 each)
What is the differnece between Ferrocene and Acetyl ferrocene. If you have a mixture of the two compounds,
how do you separated them out of a mixture?
III. Reaction Mechanisms (12 pts,
Show the major organic salt formed when asprine is treated with 2M NaOH
2
IV. General Laboratory Knowledge (48 pts) - brief answers please.
1. (2 pts) Does aspirin have a higher solubility in dichloromethane or aqueous base?
2. (2 pts) Does Acetaminophen have a higher solubility in dichoromethane or ethanol? Explain Why?
3. (2 pts) What device is used in the chemical laboratory to separate two immiscible liquids of differing density
(a device you used this session)?
4. (2 pts) What is a key feature of a good recrystallization solvent?
5. (2 pts) Impure solids generally melt at (circle one) lower / higher / the same temperature as a pure solid.
6. (2 pts) Name the ways to separate two solids from each other.
3
7.
(2 pts) When distilling an ideal binary mixture of liquids through an efficient column the pot temperature
will be (circle one) higher / lower than the head temperature.
10. (2 pts) In an extraction involving dichloromethane / water, which phase will be on top?
11. (2 pts) To extract an organic material from aqueous solution, would it be better to do one extraction with
100 mL ether or 2 extractions with 50 mL each of ether?
12. (2 pts) What are two common methods of visualizing the âspotsâ of molecules on TLC plates?
13. (2 pts) If a polar compound gives an Rf value of 0.5 using elution with 1:1 hexane : ethylacetate, what will
happen to its Rf value if the amount of ethylacetate is increased?
14. (2 pts) What is the most common stationary chromatography phases for TLC or column chromatography?
15. (2 pts) Name four functional groups that you can easily identify using IR spectrospopy
4
18. (2 pts) How can one distinguish an alcohol from an ester by IR spectroscopy?
20. (6 pts) List any problems with the following fractional distallation set up.
5
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