AAMC MCAT EXAM |ACTUAL QUESTIONS AND
VERIFIED ANSWERS|BRAND NEW 2026-2027
UPDATE|GRADED A+
Question 1
In the chromatography of the reaction mixture, water absorbed on cellulose functioned as
the stationary phase. What was the principal factor determining the migration of
individual components in the sample?
A) Hydrogen bonding
B) Solute concentration
C) Stationary phase concentration
D) Thickness of paper
CORRECT ANSWER
A) Hydrogen bonding
The answer to this question is A because the relative amount of hydrogen bonding to the
stationary phase will determine the relative rate of migration of the various components in
the sample.
Question 2
What assumption is being made if scientists conclude that aspartic acid was formed by the
prebiological synthesis in the passage?
A) Aspartic acid is unstable at temperatures below 150 degrees C.
B) All of the malic acid underwent the dehydration reaction to form fumaric/maleic acid.
C) Compound A and cyanide were available on primitive Earth.
D) The reaction between ammonia and fumaric acid was catalyzed by the presence of water.
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,CORRECT ANSWER
C) Compound A and cyanide were available on primitive Earth.
he answer to this question is C since, in order for the experimental reaction sequence to be
relevant to the primordial formation of aspartic acid, the starting materials used (Compound
A and cyanide) are assumed to have been available.
Question 3
According to the developed chromatography plate shown below, what is the approximate
Rf value of aspartic acid?
aspartic acid = 2
solvent front = 10
A) 0.20
B) 0.50
C) 5
D) 10
CORRECT ANSWER
The answer to this question is A (0.20) because Rf is the ratio of the distance travelled by the
analyte relative to the solvent front during a chromatographic separation. Aspartic acid
travelled two units, while the solvent front travelled ten units, giving an Rf of 2/10 = 0.20 for
aspartic acid.
Question 4
Which of the following statements does NOT correctly describe the dehydration of malic
acid to fumaric acid and maleic acid?
2
,A) The reaction occurs most readily with tertiary alcohols.
B) The reaction involves the loss of a water molecule.
C) The reaction has a carbocation intermediate.
D) The reaction is stereospecific.
CORRECT ANSWER
D) The reaction is stereospecific.
The answer to this question is D because the fact that both fumaric and maleic acid are
produced means that the dehydration of malic acid is NOT stereospecific.
Question 5
What type of functional group is formed when aspartic acid reacts with another amino
acid to form a peptide bond?
A) An amine group
B) An aldehyde group
C) An amide group
D) A carboxyl group
CORRECT ANSWER
C) An amide group
The answer to this question is C because the functional group that forms during peptide
bond formation is known as an amide group.
Question 6
If 2-pentanol replaces 1-pentanol in the reaction shown in Figure 3 (SN2), the rate of
substitution is less because:
3
, A) the C-O bond in 2-pentanol is stronger than the C-O bond in 1-pentanol.
B) there is a competing elimination reaction that slows the rate of substitution.
C) there is more steric hindrance at the oxygen atom in 2-pentanol than in 1-pentanol,
making protonation less likely.
D) there is more steric hindrance at the 2-position of 2-pentanol than at the 1-position of 1-
pentanol.
CORRECT ANSWER
D) there is more steric hindrance at the 2-position of 2-pentanol than at the 1-position of
1-pentanol.
The answer to this question is D because the rate of substitution of protonated alcohols is
subject to steric hindrance. This inhibits the ability of nucleophiles to collide with the
reacting electrophilic center and slows the rate of reaction.
Question 7
If a solution containing the compounds shown in Figure 4, is injected into a gas-liquid
chromatograph, the first peak observed in the gc trace is attributable to which compound?
A) Methyl-2-butanol
B) Methyl-2-butene
C) Chloro-2-methylbutane
D) Bromo-2-mehtylbutane
CORRECT ANSWER
B) Methyl-2-butene
The answer to this question is B because 2-methyl-2-butene will exhibit the lowest
molecular weight and also the weakest intermolecular forces of attraction. This substance
will therefore migrate the fastest and be the first peak in the gas chromatograph (gc) trace.
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VERIFIED ANSWERS|BRAND NEW 2026-2027
UPDATE|GRADED A+
Question 1
In the chromatography of the reaction mixture, water absorbed on cellulose functioned as
the stationary phase. What was the principal factor determining the migration of
individual components in the sample?
A) Hydrogen bonding
B) Solute concentration
C) Stationary phase concentration
D) Thickness of paper
CORRECT ANSWER
A) Hydrogen bonding
The answer to this question is A because the relative amount of hydrogen bonding to the
stationary phase will determine the relative rate of migration of the various components in
the sample.
Question 2
What assumption is being made if scientists conclude that aspartic acid was formed by the
prebiological synthesis in the passage?
A) Aspartic acid is unstable at temperatures below 150 degrees C.
B) All of the malic acid underwent the dehydration reaction to form fumaric/maleic acid.
C) Compound A and cyanide were available on primitive Earth.
D) The reaction between ammonia and fumaric acid was catalyzed by the presence of water.
1
,CORRECT ANSWER
C) Compound A and cyanide were available on primitive Earth.
he answer to this question is C since, in order for the experimental reaction sequence to be
relevant to the primordial formation of aspartic acid, the starting materials used (Compound
A and cyanide) are assumed to have been available.
Question 3
According to the developed chromatography plate shown below, what is the approximate
Rf value of aspartic acid?
aspartic acid = 2
solvent front = 10
A) 0.20
B) 0.50
C) 5
D) 10
CORRECT ANSWER
The answer to this question is A (0.20) because Rf is the ratio of the distance travelled by the
analyte relative to the solvent front during a chromatographic separation. Aspartic acid
travelled two units, while the solvent front travelled ten units, giving an Rf of 2/10 = 0.20 for
aspartic acid.
Question 4
Which of the following statements does NOT correctly describe the dehydration of malic
acid to fumaric acid and maleic acid?
2
,A) The reaction occurs most readily with tertiary alcohols.
B) The reaction involves the loss of a water molecule.
C) The reaction has a carbocation intermediate.
D) The reaction is stereospecific.
CORRECT ANSWER
D) The reaction is stereospecific.
The answer to this question is D because the fact that both fumaric and maleic acid are
produced means that the dehydration of malic acid is NOT stereospecific.
Question 5
What type of functional group is formed when aspartic acid reacts with another amino
acid to form a peptide bond?
A) An amine group
B) An aldehyde group
C) An amide group
D) A carboxyl group
CORRECT ANSWER
C) An amide group
The answer to this question is C because the functional group that forms during peptide
bond formation is known as an amide group.
Question 6
If 2-pentanol replaces 1-pentanol in the reaction shown in Figure 3 (SN2), the rate of
substitution is less because:
3
, A) the C-O bond in 2-pentanol is stronger than the C-O bond in 1-pentanol.
B) there is a competing elimination reaction that slows the rate of substitution.
C) there is more steric hindrance at the oxygen atom in 2-pentanol than in 1-pentanol,
making protonation less likely.
D) there is more steric hindrance at the 2-position of 2-pentanol than at the 1-position of 1-
pentanol.
CORRECT ANSWER
D) there is more steric hindrance at the 2-position of 2-pentanol than at the 1-position of
1-pentanol.
The answer to this question is D because the rate of substitution of protonated alcohols is
subject to steric hindrance. This inhibits the ability of nucleophiles to collide with the
reacting electrophilic center and slows the rate of reaction.
Question 7
If a solution containing the compounds shown in Figure 4, is injected into a gas-liquid
chromatograph, the first peak observed in the gc trace is attributable to which compound?
A) Methyl-2-butanol
B) Methyl-2-butene
C) Chloro-2-methylbutane
D) Bromo-2-mehtylbutane
CORRECT ANSWER
B) Methyl-2-butene
The answer to this question is B because 2-methyl-2-butene will exhibit the lowest
molecular weight and also the weakest intermolecular forces of attraction. This substance
will therefore migrate the fastest and be the first peak in the gas chromatograph (gc) trace.
4
