mcat practice exam 1 Exam Questions
and Answers 2025/2026(Complete
Practice Papers)
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? - CORRECT ANSWERS Hydrogen bonding
What assumption is being made if scientists conclude that aspartic acid was formed by the prebiological
synthesis in the passage? - CORRECT ANSWERS Compound A and cyanide were available on
primitive Earth.
Which of the following statements does NOT correctly describe the dehydration of malic acid to fumaric
acid and maleic acid? - CORRECT ANSWERS The reaction is stereospecific.
What type of functional group is formed when aspartic acid reacts with another amino acid to form a
peptide bond? - CORRECT ANSWERS .An amide group
If 2-pentanol replaces 1-pentanol in the reaction shown in Figure 3, the rate of substitution is less
because: - CORRECT ANSWERS there is more steric hindrance at the 2-position of 2-pentanol
than at the 1-position of 1-pentanol.
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
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? - CORRECT ANSWERS
2-Methyl-2-butene
, 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.
Acetic acid and ethanol react to form an ester product as shown below.
In determining which reactant loses the -OH group, which of the following isotopic substitutions would
be most useful? - CORRECT ANSWERS Replace the hydroxyl oxygen of ethanol with O-18.
this experiment involves labeling a group which does not exchange with other groups present prior to
reaction and will therefore give information about the true identity of the groups, which are exchanged
during the reaction.
A person, whose eye has a lens-to-retina distance of 2.0 cm, can only clearly see objects that are closer
than 1.0 m away. What is the strength S of the person's eye lens? (Note: Use the thin lens formula
1/O+1/I=S.) - CORRECT ANSWERS 51 D
Which statement correctly describes how enzymes affect chemical reactions? Stabilization of: -
CORRECT ANSWERS the transition state changes the activation energy of the reaction.
Which of the following will decrease the percentage ionization of 1.0 M acetic acid, CH3CO2H(aq)? -
CORRECT ANSWERS Adding concentrated HCl(aq)
HCl is a strong acid that will increase the amount of H+ in solution and thus decrease the percentage of
CH3CO2H that ionizes.
When the current in the micro-robot's circuit increases and the resistance of the circuit remains
constant, the voltage of the circuit: - CORRECT ANSWERS increases.
and Answers 2025/2026(Complete
Practice Papers)
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? - CORRECT ANSWERS Hydrogen bonding
What assumption is being made if scientists conclude that aspartic acid was formed by the prebiological
synthesis in the passage? - CORRECT ANSWERS Compound A and cyanide were available on
primitive Earth.
Which of the following statements does NOT correctly describe the dehydration of malic acid to fumaric
acid and maleic acid? - CORRECT ANSWERS The reaction is stereospecific.
What type of functional group is formed when aspartic acid reacts with another amino acid to form a
peptide bond? - CORRECT ANSWERS .An amide group
If 2-pentanol replaces 1-pentanol in the reaction shown in Figure 3, the rate of substitution is less
because: - CORRECT ANSWERS there is more steric hindrance at the 2-position of 2-pentanol
than at the 1-position of 1-pentanol.
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
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? - CORRECT ANSWERS
2-Methyl-2-butene
, 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.
Acetic acid and ethanol react to form an ester product as shown below.
In determining which reactant loses the -OH group, which of the following isotopic substitutions would
be most useful? - CORRECT ANSWERS Replace the hydroxyl oxygen of ethanol with O-18.
this experiment involves labeling a group which does not exchange with other groups present prior to
reaction and will therefore give information about the true identity of the groups, which are exchanged
during the reaction.
A person, whose eye has a lens-to-retina distance of 2.0 cm, can only clearly see objects that are closer
than 1.0 m away. What is the strength S of the person's eye lens? (Note: Use the thin lens formula
1/O+1/I=S.) - CORRECT ANSWERS 51 D
Which statement correctly describes how enzymes affect chemical reactions? Stabilization of: -
CORRECT ANSWERS the transition state changes the activation energy of the reaction.
Which of the following will decrease the percentage ionization of 1.0 M acetic acid, CH3CO2H(aq)? -
CORRECT ANSWERS Adding concentrated HCl(aq)
HCl is a strong acid that will increase the amount of H+ in solution and thus decrease the percentage of
CH3CO2H that ionizes.
When the current in the micro-robot's circuit increases and the resistance of the circuit remains
constant, the voltage of the circuit: - CORRECT ANSWERS increases.
