AAMC MCAT 2026 CORE EXAMS TEST QUESTIONS AND
ANSWERS GUARANTEE A+
✔✔The intermolecular forces that exist among the molecules of NH3 gas are:
A.
dipole-dipole forces only.
B.
London dispersion forces only.
C.
both dipole-dipole and London dispersion forces.
D.
neither dipole-dipole nor London dispersion forces. - ✔✔C.
both dipole-dipole and London dispersion forces., Since NH3 is a permanent dipole, it
will exhibit dipole-dipole intermolecular forces in addition to the London dispersion
forces exhibited by all molecules
✔✔dipole-dipole forces - ✔✔attractions between oppositely charged regions of polar
molecules
✔✔London dispersion forces - ✔✔the intermolecular attraction resulting from the
uneven distribution of electrons and the creation of temporary dipoles
✔✔NH3 acts as a weak base in water with Kb = 1.76 × 10-5 at 25°C. The
corresponding equilibrium is shown below.
NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq)
At 25°C, the equilibrium concentration of the NH4+ ion in a 10 M aqueous solution of
NH3 would be closest to which of the following?
A.
0.001 M
B.
0.01 M
C.
0.1 M
D.
1 M - ✔✔C.
0.1 M, Kb = 1.76 × 10-5 = [NH4+][OH-]/[NH3]. Plugging in 10 M for [NH3], which is a
good approximation since very little NH3 ionizes, and noting that [NH4+] = [OH-], it is
possible to solve for [NH4+]: 1.76 × 10-5 = [NH4+]2/10 → 1.76 × 10-4 = [NH4+]2 →
1.32 × 10-2 = [NH4+].
✔✔If methane (CH4) were substituted for NH3 in the aluminum can, the crushing of the
can would:
A.
occur because CH4, being polar, would dissolve in the water in the tray.
B.
,occur because CH4, being nonpolar, would dissolve in the water in the tray.
C.
not occur because CH4, being polar, would not dissolve in the water in the tray.
D.
not occur because CH4, being nonpolar, would not dissolve in the water in the tray. -
✔✔D.
not occur because CH4, being nonpolar, would not dissolve in the water in the tray.,
CH4 is a nonpolar molecule and will not dissolve appreciably in water. Since the CH4
will remain in the gas phase, the can will not be crushed by the formation of a vacuum
inside the can.
✔✔Ca(OH)2 and CaCl2 in the reaction shown in Equation 1 are best described as
compounds of:
A.
an alkali metal.
B.
an alkaline earth metal.
C.
a metalloid.
D.
a transition metal.
Solution - ✔✔B.
an alkaline earth metal., Group 2 of the Periodic Table. Calcium, Ca, is a member of this
family found in period 4
✔✔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. - ✔✔A.
Compound 1 selectively sensitizes cancer cells to chemotherapeutic action by
Compound 2.
✔✔What is the concentration of the acute leukemia CC95 Combination value in
micromolar (μM) units?
A.
6 × 10-10 μM
B.
6 × 10-7 μM
,C.
6 × 10- 4 μM
D.
6 × 10-2 μM - ✔✔C.
6 × 10- 4 μM, The CC95 Combination value for acute leukemia cells was 0.6 nM, or 0.6
× 10-9 M. This corresponds to 0.6 × 10-9 M × (1 μM/1 × 10-6 M) = 0.6 × 10-3 μM = 6 ×
10-4 μM.
✔✔Compared to treatment with Compound 2 alone, which cell line shows the greatest
enhancement of chemotherapeutic activity as a result of sensitization by Compound 1?
A.
Acute leukemia
B.
Fibrosarcoma
C.
Cervical carcinoma
D.
Noncancerous fibroblast - ✔✔A.
Acute leukemia, The ratio of the values of CC95 to CC95 Combination, gives the "fold
enhancement" that is produced by using a combination of compounds 1 and 2 instead
of just Compound 2 alone. Acute leukemia cells show a 74-fold enhancement in
apoptotic activity by using the combination of compounds 1 and 2, while the other
cancer cell lines show only a roughly 10-fold enhancement.
✔✔Assume that cellular uptake rates and drug delivery rates of compounds 1 and 2 are
identical. If the proposed mechanism of sensitization by Compound 1 is correct, what
cancer cell treatment protocol is most likely to produce the most apoptosis 20 h after
treatment?
A.
Administration of both Compound 1 and Compound 2 simultaneously
B.
Administration of Compound 1 followed by Compound 2 after 0.5 h
C.
Administration of Compound 2 followed by Compound 1 after 0.5 h
D.
Administration of Compound 2 followed by Compound 1 after 1 d
Solution - ✔✔B.
Administration of Compound 1 followed by Compound 2 after 0.5 h, NF-κB signaling
pathway is anti-apoptotic and is initiated by degradation and release of the inhibitor
binding protein IκB. Once started, this process is not easily reversed. If the
chemotherapeutic agent is administered at the same time as the sensitization agent,
there is good reason to believe that some cells will be exposed to Compound 2 prior to
Compound 1 as a result of random probability. The researchers found that
administration of Compound 1 prior to Compound 2 by 0.5 h provided benefit.
, ✔✔A carbonyl group contains what type of bonding interaction(s) between the C and O
atoms?
A.
One σ only
B.
One σ and one π only
C.
One π only
D.
One σ and two π only - ✔✔B.
One σ and one π only, C=O double bond. The first bonding interaction between atoms
is always a σ bond. The second bond is formed from π symmetry orbitals.
✔✔Which of the following atoms gains one electron most readily?
A.
Ar
B.
Br
C.
Co
D.
Na - ✔✔B.
Br, Atoms positioned to the right of the Periodic Table tend to gain electrons more
readily than the metallic elements on the left, with the exception of Group 18. Bromine,
Br, is a member of the Group 17 halogen family and gains an electron readily.
✔✔Which transition produces a photon with the longest wavelength?
A.
Transition 1
B.
Transition 2
C.
Transition 3
D.
Transition 4 - ✔✔B.
Transition 2, The separation between the energy level equals the energy of the photon.
The energy of the photon is inversely proportional to the wavelength. The longest
wavelength corresponds to the smallest photon energy, which corresponds to the
transition between the closest energy levels.
✔✔Which of the following functional groups is present in pyrrolizidine (Figure 1)?
A.
An amide
B.
An amine
ANSWERS GUARANTEE A+
✔✔The intermolecular forces that exist among the molecules of NH3 gas are:
A.
dipole-dipole forces only.
B.
London dispersion forces only.
C.
both dipole-dipole and London dispersion forces.
D.
neither dipole-dipole nor London dispersion forces. - ✔✔C.
both dipole-dipole and London dispersion forces., Since NH3 is a permanent dipole, it
will exhibit dipole-dipole intermolecular forces in addition to the London dispersion
forces exhibited by all molecules
✔✔dipole-dipole forces - ✔✔attractions between oppositely charged regions of polar
molecules
✔✔London dispersion forces - ✔✔the intermolecular attraction resulting from the
uneven distribution of electrons and the creation of temporary dipoles
✔✔NH3 acts as a weak base in water with Kb = 1.76 × 10-5 at 25°C. The
corresponding equilibrium is shown below.
NH3(aq) + H2O(l) ⇌ NH4+(aq) + OH-(aq)
At 25°C, the equilibrium concentration of the NH4+ ion in a 10 M aqueous solution of
NH3 would be closest to which of the following?
A.
0.001 M
B.
0.01 M
C.
0.1 M
D.
1 M - ✔✔C.
0.1 M, Kb = 1.76 × 10-5 = [NH4+][OH-]/[NH3]. Plugging in 10 M for [NH3], which is a
good approximation since very little NH3 ionizes, and noting that [NH4+] = [OH-], it is
possible to solve for [NH4+]: 1.76 × 10-5 = [NH4+]2/10 → 1.76 × 10-4 = [NH4+]2 →
1.32 × 10-2 = [NH4+].
✔✔If methane (CH4) were substituted for NH3 in the aluminum can, the crushing of the
can would:
A.
occur because CH4, being polar, would dissolve in the water in the tray.
B.
,occur because CH4, being nonpolar, would dissolve in the water in the tray.
C.
not occur because CH4, being polar, would not dissolve in the water in the tray.
D.
not occur because CH4, being nonpolar, would not dissolve in the water in the tray. -
✔✔D.
not occur because CH4, being nonpolar, would not dissolve in the water in the tray.,
CH4 is a nonpolar molecule and will not dissolve appreciably in water. Since the CH4
will remain in the gas phase, the can will not be crushed by the formation of a vacuum
inside the can.
✔✔Ca(OH)2 and CaCl2 in the reaction shown in Equation 1 are best described as
compounds of:
A.
an alkali metal.
B.
an alkaline earth metal.
C.
a metalloid.
D.
a transition metal.
Solution - ✔✔B.
an alkaline earth metal., Group 2 of the Periodic Table. Calcium, Ca, is a member of this
family found in period 4
✔✔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. - ✔✔A.
Compound 1 selectively sensitizes cancer cells to chemotherapeutic action by
Compound 2.
✔✔What is the concentration of the acute leukemia CC95 Combination value in
micromolar (μM) units?
A.
6 × 10-10 μM
B.
6 × 10-7 μM
,C.
6 × 10- 4 μM
D.
6 × 10-2 μM - ✔✔C.
6 × 10- 4 μM, The CC95 Combination value for acute leukemia cells was 0.6 nM, or 0.6
× 10-9 M. This corresponds to 0.6 × 10-9 M × (1 μM/1 × 10-6 M) = 0.6 × 10-3 μM = 6 ×
10-4 μM.
✔✔Compared to treatment with Compound 2 alone, which cell line shows the greatest
enhancement of chemotherapeutic activity as a result of sensitization by Compound 1?
A.
Acute leukemia
B.
Fibrosarcoma
C.
Cervical carcinoma
D.
Noncancerous fibroblast - ✔✔A.
Acute leukemia, The ratio of the values of CC95 to CC95 Combination, gives the "fold
enhancement" that is produced by using a combination of compounds 1 and 2 instead
of just Compound 2 alone. Acute leukemia cells show a 74-fold enhancement in
apoptotic activity by using the combination of compounds 1 and 2, while the other
cancer cell lines show only a roughly 10-fold enhancement.
✔✔Assume that cellular uptake rates and drug delivery rates of compounds 1 and 2 are
identical. If the proposed mechanism of sensitization by Compound 1 is correct, what
cancer cell treatment protocol is most likely to produce the most apoptosis 20 h after
treatment?
A.
Administration of both Compound 1 and Compound 2 simultaneously
B.
Administration of Compound 1 followed by Compound 2 after 0.5 h
C.
Administration of Compound 2 followed by Compound 1 after 0.5 h
D.
Administration of Compound 2 followed by Compound 1 after 1 d
Solution - ✔✔B.
Administration of Compound 1 followed by Compound 2 after 0.5 h, NF-κB signaling
pathway is anti-apoptotic and is initiated by degradation and release of the inhibitor
binding protein IκB. Once started, this process is not easily reversed. If the
chemotherapeutic agent is administered at the same time as the sensitization agent,
there is good reason to believe that some cells will be exposed to Compound 2 prior to
Compound 1 as a result of random probability. The researchers found that
administration of Compound 1 prior to Compound 2 by 0.5 h provided benefit.
, ✔✔A carbonyl group contains what type of bonding interaction(s) between the C and O
atoms?
A.
One σ only
B.
One σ and one π only
C.
One π only
D.
One σ and two π only - ✔✔B.
One σ and one π only, C=O double bond. The first bonding interaction between atoms
is always a σ bond. The second bond is formed from π symmetry orbitals.
✔✔Which of the following atoms gains one electron most readily?
A.
Ar
B.
Br
C.
Co
D.
Na - ✔✔B.
Br, Atoms positioned to the right of the Periodic Table tend to gain electrons more
readily than the metallic elements on the left, with the exception of Group 18. Bromine,
Br, is a member of the Group 17 halogen family and gains an electron readily.
✔✔Which transition produces a photon with the longest wavelength?
A.
Transition 1
B.
Transition 2
C.
Transition 3
D.
Transition 4 - ✔✔B.
Transition 2, The separation between the energy level equals the energy of the photon.
The energy of the photon is inversely proportional to the wavelength. The longest
wavelength corresponds to the smallest photon energy, which corresponds to the
transition between the closest energy levels.
✔✔Which of the following functional groups is present in pyrrolizidine (Figure 1)?
A.
An amide
B.
An amine
