Chem 238 Lab Final Questions With Complete Solutions
A&K
Choose the correct order of steps for the Iodoform test with a
methyl carbinol -
a. oxidation, iodoform formation, iodination
b. iodoform formation, Iodination, oxidation
c. oxidation, iodination, iodoform formation
d. reduction, iodination, iodoform formation Correct Answers
C
A&K
In the 2,4-DNP test, which of the following will not produce a
precipitate?
a. aldehydes
b. ketones
c. lactones
d. all will produce precipitate Correct Answers C
A&K
In the Iodoform test, each of the following is correct except:
a. positive results for compounds with a methyl group attached
to the functional carbon in methyl ketones
b. if compound is ethanol, it produces a negative result
c. Iodoform is visible as a bright yellow precipitate, has a sharp
sweet antiseptic smell
d. the only aldehyde that will give a positive result is
acetaldehyde Correct Answers B
A&K
Schiff's test uses what reagent?
,a. Rosanaline hydrochloride
b. silver salts
c. an aldehyde
d. a ketone Correct Answers A
A&K
What does 2,4-DNP Test reveal about your compound?
a. that you have a methyl group adjacent to C=O
b. that you have an ester group
c. that an aldehyde or ketone is present
d. that you have an alcohol group Correct Answers C
A&K
What is the safety issue associated with long term storage of
Tollen's reagent?
a. it is toxic and corrosive
b. it produces iodine vapor
c. it forms an explosive precipitation
d. it is completely safe Correct Answers C
A&K
What region of your infrared spectrum allows you to distinguish
an aldehyde from a ketone?
a. 3200-3600
b. 2700
c. 1400
d. 1540 Correct Answers B
A&K
When a Schiff's test is performed on 3-pentanone, what
happens?
, a. a silver mirror appears
b. a yellow precipitate forms
c. a color change occurs
d. there is no charge Correct Answers D
A&K
Which of the following carbonyl containing compounds will
give a positive result with Tollen's reagent?
a. formaldehyde
b. acetone
c. acetic acid
d. dimethylformamide Correct Answers A
A&K
Which of the following techniques/methods will not be used to
identify the unknown in the A&K experiment today?
a. derivatization
b. recrystallization
c. solubility test
d. UV absorbance Correct Answers D
A&K
Which of the following will show positive results with Schiff's
test most rapidly?
a. aldehyde
b. benzaldehyde
c. oxo-benzene
d. ketone Correct Answers A
Aldol
Aldol condensation reactions can be catalyzed by:
A&K
Choose the correct order of steps for the Iodoform test with a
methyl carbinol -
a. oxidation, iodoform formation, iodination
b. iodoform formation, Iodination, oxidation
c. oxidation, iodination, iodoform formation
d. reduction, iodination, iodoform formation Correct Answers
C
A&K
In the 2,4-DNP test, which of the following will not produce a
precipitate?
a. aldehydes
b. ketones
c. lactones
d. all will produce precipitate Correct Answers C
A&K
In the Iodoform test, each of the following is correct except:
a. positive results for compounds with a methyl group attached
to the functional carbon in methyl ketones
b. if compound is ethanol, it produces a negative result
c. Iodoform is visible as a bright yellow precipitate, has a sharp
sweet antiseptic smell
d. the only aldehyde that will give a positive result is
acetaldehyde Correct Answers B
A&K
Schiff's test uses what reagent?
,a. Rosanaline hydrochloride
b. silver salts
c. an aldehyde
d. a ketone Correct Answers A
A&K
What does 2,4-DNP Test reveal about your compound?
a. that you have a methyl group adjacent to C=O
b. that you have an ester group
c. that an aldehyde or ketone is present
d. that you have an alcohol group Correct Answers C
A&K
What is the safety issue associated with long term storage of
Tollen's reagent?
a. it is toxic and corrosive
b. it produces iodine vapor
c. it forms an explosive precipitation
d. it is completely safe Correct Answers C
A&K
What region of your infrared spectrum allows you to distinguish
an aldehyde from a ketone?
a. 3200-3600
b. 2700
c. 1400
d. 1540 Correct Answers B
A&K
When a Schiff's test is performed on 3-pentanone, what
happens?
, a. a silver mirror appears
b. a yellow precipitate forms
c. a color change occurs
d. there is no charge Correct Answers D
A&K
Which of the following carbonyl containing compounds will
give a positive result with Tollen's reagent?
a. formaldehyde
b. acetone
c. acetic acid
d. dimethylformamide Correct Answers A
A&K
Which of the following techniques/methods will not be used to
identify the unknown in the A&K experiment today?
a. derivatization
b. recrystallization
c. solubility test
d. UV absorbance Correct Answers D
A&K
Which of the following will show positive results with Schiff's
test most rapidly?
a. aldehyde
b. benzaldehyde
c. oxo-benzene
d. ketone Correct Answers A
Aldol
Aldol condensation reactions can be catalyzed by:
