CHEM 335 Exam 2 Questions and Answers Graded A+ Latest Update 2025-2026
Which of the following statements are TRUE concerning this laboratory exercise - The systematic
identification of an organic compound?
In a "real world" situation, the compound could be one of several million possible known organic
compounds
Your unknown may be a solid, liquid, or gas.
Your compound will contain at least C, H, and oxygen and one or more of several possible elements such
as N, one or more halogens, S and Se.
You can use spectroscopic results to indicate the appropriate chemical tests to perform
Your compound, when you analyze it, may be impure, ie, a component of a mixture - Answers TRUE: In a
"real world" situation, the compound could be one of several million possible known organic
compounds
FALSE: Your unknown may be a solid, liquid, or gas.
FALSE: Your compound will contain at least C, H, and oxygen and one or more of several possible
elements such as N, one or more halogens, S and Se.
FALSE: You can use spectroscopic results to indicate the appropriate chemical tests to perform
FALSE: Your compound, when you analyze it, may be impure, ie, a component of a mixture
A positive test with 2,4 dinitrophenylhydrazine could indicate the presence of which of the following
function groups?
,alkenes
amines
carboxylic acids
ketones
alcohols - Answers ketones
Which classification test is used to tell apart (differentiate) an aldehyde from a ketone?
acetyl chloride test
bicarbonate test
chromic acid test
bromine test
2,4-dinitrophenylhydrazine (DNPH) test - Answers chromic acid test
The compound shown will give clues to its structure by which of the following spectral features?
(Assume there is no magnetic coupling with the aldehyde proton)
A sharp singlet in the region of delta=3.5 ppm (NMR)
An important pair of moderately strong absorptions at about 800. and 900 wavenumbers IR)
A triplet at about delta = 2.2 ppm, integrating for 2 protons (NMR)
, A strong, sharp absorption at about 1730 wavenumbers (IR)
A strong, broad absorption at about 3300 wavenumbers (IR) - Answers FALSE: A sharp singlet in the
region of delta=3.5 ppm (NMR)
FALSE: An important pair of moderately strong absorptions at about 800. and 900 wavenumbers IR)
TRUE: A triplet at about delta = 2.2 ppm, integrating for 2 protons (NMR)
TRUE: A strong, sharp absorption at about 1730 wavenumbers (IR)
FALSE: A strong, broad absorption at about 3300 wavenumbers (IR)
Which of the following reagents would give positive tests for the following molecule? (an ketone with
and has a bromine)
Bromine in carbon tetrachloride
2,4-dinitrophenylhydrazine
acetyl chloride
chromic acid - Jones reagent
potassium permangeate - Answers TRUE: Bromine in carbon tetrachloride
TRUE: 2,4-dinitrophenylhydrazine
Which of the following statements are TRUE concerning this laboratory exercise - The systematic
identification of an organic compound?
In a "real world" situation, the compound could be one of several million possible known organic
compounds
Your unknown may be a solid, liquid, or gas.
Your compound will contain at least C, H, and oxygen and one or more of several possible elements such
as N, one or more halogens, S and Se.
You can use spectroscopic results to indicate the appropriate chemical tests to perform
Your compound, when you analyze it, may be impure, ie, a component of a mixture - Answers TRUE: In a
"real world" situation, the compound could be one of several million possible known organic
compounds
FALSE: Your unknown may be a solid, liquid, or gas.
FALSE: Your compound will contain at least C, H, and oxygen and one or more of several possible
elements such as N, one or more halogens, S and Se.
FALSE: You can use spectroscopic results to indicate the appropriate chemical tests to perform
FALSE: Your compound, when you analyze it, may be impure, ie, a component of a mixture
A positive test with 2,4 dinitrophenylhydrazine could indicate the presence of which of the following
function groups?
,alkenes
amines
carboxylic acids
ketones
alcohols - Answers ketones
Which classification test is used to tell apart (differentiate) an aldehyde from a ketone?
acetyl chloride test
bicarbonate test
chromic acid test
bromine test
2,4-dinitrophenylhydrazine (DNPH) test - Answers chromic acid test
The compound shown will give clues to its structure by which of the following spectral features?
(Assume there is no magnetic coupling with the aldehyde proton)
A sharp singlet in the region of delta=3.5 ppm (NMR)
An important pair of moderately strong absorptions at about 800. and 900 wavenumbers IR)
A triplet at about delta = 2.2 ppm, integrating for 2 protons (NMR)
, A strong, sharp absorption at about 1730 wavenumbers (IR)
A strong, broad absorption at about 3300 wavenumbers (IR) - Answers FALSE: A sharp singlet in the
region of delta=3.5 ppm (NMR)
FALSE: An important pair of moderately strong absorptions at about 800. and 900 wavenumbers IR)
TRUE: A triplet at about delta = 2.2 ppm, integrating for 2 protons (NMR)
TRUE: A strong, sharp absorption at about 1730 wavenumbers (IR)
FALSE: A strong, broad absorption at about 3300 wavenumbers (IR)
Which of the following reagents would give positive tests for the following molecule? (an ketone with
and has a bromine)
Bromine in carbon tetrachloride
2,4-dinitrophenylhydrazine
acetyl chloride
chromic acid - Jones reagent
potassium permangeate - Answers TRUE: Bromine in carbon tetrachloride
TRUE: 2,4-dinitrophenylhydrazine
