AAMC MCAT Exam 4- Chem/Phys
2022/2023
Limestone does NOT decompose when heated to 900 K because, at 900 K, ΔH is:
A.
positive and less than TΔS.
B.
positive and greater than TΔS.
C.
negative and less than TΔS.
D.
negative and greater than TΔS. - ANSWER B.
positive and greater than TΔS.
The reaction does not occur (is not spontaneous). This indicates that ΔG = ΔH - TΔS >
0. From inspection of the reaction, it can be concluded that ΔS > 0 (a gas evolves).
Consequently, ΔH > TΔS explains why the reaction does not occur.
According to Table 1, what is the concentration of the glucose in the blood from which
the diluted sample was taken?
A.
60 mg/dL
B.
90 mg/dL
C.
120 mg/dL
D.
150 mg/dL - ANSWER D. 150 mg/dL
From Table 1, the glucose concentration in the diluted sample is (0.20/0.24) × 6.0
mg/dL = 5.0 mg/dL. The blood then has a glucose concentration of 30 × 5.0 mg/dL =
150 mg/dL.
Which of the following oxidative transformations is unlikely to occur?
A.
A primary alcohol to an aldehyde
B.
A tertiary alcohol to a ketone
C.
An aldehyde to a carboxylic acid
D.
A secondary alcohol to a ketone - ANSWER B. A tertiary alcohol to a ketone
, Oxidation of tertiary alcohols is difficult because it involves C-C bond breaking.
What is the effect produced by the PRK technique designed to correct
nearsightedness?
A.
The density of the cornea is increased.
B.
The radius of curvature of the cornea is increased.
C.
The index of refraction of the cornea is increased.
D.
The thickness of the cornea at the apex is increased. - ANSWER B.
The radius of curvature of the cornea is increased.
in passage, it says nearsightedness flattens the cornea. Flattening the cornea would
increase the radius of curvature.
The use of pulsed laser radiation in the PRK procedure, as opposed to continuous laser
radiation, allows the cornea to:
A.
absorb more radiation.
B.
change its index of refraction.
C.
increase the area exposed to radiation.
D.
maintain a lower average temperature. - ANSWER D.
maintain a lower average temperature.
The pulsed laser radiation interacts with the cornea for a shorter time than a continuous
laser radiation, thus less heat is transferred to the cornea. This allows the cornea to
maintain a lower average temperature by cooling off between pu
Which conclusion can be drawn from the experimental results described in the
passage?
A.
Compound 1 selectively sensitizes cancer cells to chemotherapeutic action by
Compound 2.
B.
Compound 1 sensitizes all cells to chemotherapeutic action.
C.
Compound 2 induces apoptosis in cancer cells only in conjunction with treatment with
Compound 1.
D.
Compound 2 inhibits the NF-κB signaling pathway, which leads to apoptosis. -
ANSWER A.
2022/2023
Limestone does NOT decompose when heated to 900 K because, at 900 K, ΔH is:
A.
positive and less than TΔS.
B.
positive and greater than TΔS.
C.
negative and less than TΔS.
D.
negative and greater than TΔS. - ANSWER B.
positive and greater than TΔS.
The reaction does not occur (is not spontaneous). This indicates that ΔG = ΔH - TΔS >
0. From inspection of the reaction, it can be concluded that ΔS > 0 (a gas evolves).
Consequently, ΔH > TΔS explains why the reaction does not occur.
According to Table 1, what is the concentration of the glucose in the blood from which
the diluted sample was taken?
A.
60 mg/dL
B.
90 mg/dL
C.
120 mg/dL
D.
150 mg/dL - ANSWER D. 150 mg/dL
From Table 1, the glucose concentration in the diluted sample is (0.20/0.24) × 6.0
mg/dL = 5.0 mg/dL. The blood then has a glucose concentration of 30 × 5.0 mg/dL =
150 mg/dL.
Which of the following oxidative transformations is unlikely to occur?
A.
A primary alcohol to an aldehyde
B.
A tertiary alcohol to a ketone
C.
An aldehyde to a carboxylic acid
D.
A secondary alcohol to a ketone - ANSWER B. A tertiary alcohol to a ketone
, Oxidation of tertiary alcohols is difficult because it involves C-C bond breaking.
What is the effect produced by the PRK technique designed to correct
nearsightedness?
A.
The density of the cornea is increased.
B.
The radius of curvature of the cornea is increased.
C.
The index of refraction of the cornea is increased.
D.
The thickness of the cornea at the apex is increased. - ANSWER B.
The radius of curvature of the cornea is increased.
in passage, it says nearsightedness flattens the cornea. Flattening the cornea would
increase the radius of curvature.
The use of pulsed laser radiation in the PRK procedure, as opposed to continuous laser
radiation, allows the cornea to:
A.
absorb more radiation.
B.
change its index of refraction.
C.
increase the area exposed to radiation.
D.
maintain a lower average temperature. - ANSWER D.
maintain a lower average temperature.
The pulsed laser radiation interacts with the cornea for a shorter time than a continuous
laser radiation, thus less heat is transferred to the cornea. This allows the cornea to
maintain a lower average temperature by cooling off between pu
Which conclusion can be drawn from the experimental results described in the
passage?
A.
Compound 1 selectively sensitizes cancer cells to chemotherapeutic action by
Compound 2.
B.
Compound 1 sensitizes all cells to chemotherapeutic action.
C.
Compound 2 induces apoptosis in cancer cells only in conjunction with treatment with
Compound 1.
D.
Compound 2 inhibits the NF-κB signaling pathway, which leads to apoptosis. -
ANSWER A.
