MCAT Diagnostic Test Review with
correct answers
vWhich of the following correctly lists the floating lag times for the three trials in
increasing order, assuming that when mixing the drug and polymer, the density of
either component doesn't change? - answer C. Trial 3 < Trial 2 < Trial 1
Explanation:
Key word is "floating lag times". Per common knowledge, an object with lesser density
will float faster than one of greater density. Looking at "Bulk Density" of Table 1, which
shows the densities of each polymer, choice C is the correct answer.
Why I got it wrong:
I skipped words when reading the question and focused on "lag times", a phrase I
didn't understand.
How to fix it:
Read and highlight the question carefully.
Tolazamide is an aromatic drug with a similar sulfonylurea structure to glipizide.
Which of the following is most likely tolazamide? - answer A.
Explanation:
First, it is indicated that tolazamide is an "aromatic" drug, so that eliminates choice D.
The key word is "sulfonylurea", which as the name suggests, contains sulfonyl and
urea groups.
Sulfonyl group: O=S=O
Urea group: CH4N2O
Why I got it wrong:
I didn't read the passage carefully enough to find the "sulfonylurea" clue. I also didn't
know what urea was.
How to fix it:
Carefully find the key word, "glipizide", in the passage and look for words that describe
it. Memorize structure of urea.
A student preparing for the experiments inadvertently adds an additional 400 mL of
the same acid solution to the dissolution vessel. What will be the new pOH of this
solution? - answer D. 13.0
Explanation:
, READ THE QUESTION, the answer should be pOH, which should be >7 for conc. acid,
eliminating choices A and B. When concentration remains the same, volume change
doesn't affect pH. The formula for pH is pH = -log[H]. [H] is given to be 0.1 M. Plug it
into the equation to get pH = 1, and 14 - 1 = 13 for pOH.
Why I got it wrong:
I didn't read the question carefully to see that it was asking for pOH.
How to fix it:
Read question carefully and highlight what it's asking for.
Stomach contents empty with an initial flow rate of 0.67 cm3/sec. Patients who
undergo gastric bypass surgery will increase this rate by a factor of 16. Assuming that
the flow of stomach contents approximates Poiseuille's Law, what change to their
gastrointestinal connection would explain this, provided no other changes occur that
affect stomach content flow? - answer C. The new connection radius is 2x larger.
Explanation:
According to Poiseuille's Law, Flow = ΔPπr^Lη. In this equation, ΔP is the
pressure difference across the pipe, r is the radius of the pipe, L is the length of the
pipe, and η is the viscosity of the fluid in the pipe. The question states that the flow
increased by a factor of 16. If every other variable remains constant, only 2^4 would
give 16. Thus the radius is 2.
Why I got it wrong:
I have no idea what Poiseuille's Law was.
How to fix it:
Memorize Poiseuille's Law.
When in vivo studies were performed on the three drug-polymer combinations, it was
found patients in the PolOxAemer-188 group experienced the most stomach pains
after administration. Given the results of the study, this is MOST likely due to: - answer
B. tablet fragments causing inflammation of the gastric mucosa.
Explanation:
In Figure 1, trial 3 showed the lowest percent of drug release, which shows the least
solubility. This could lead to undissolved tablet fragments, which is choice B.
Why I got it wrong:
I did not read the discussion below Figure 1, and missed the sentences about
solubility.
How to fix it:
correct answers
vWhich of the following correctly lists the floating lag times for the three trials in
increasing order, assuming that when mixing the drug and polymer, the density of
either component doesn't change? - answer C. Trial 3 < Trial 2 < Trial 1
Explanation:
Key word is "floating lag times". Per common knowledge, an object with lesser density
will float faster than one of greater density. Looking at "Bulk Density" of Table 1, which
shows the densities of each polymer, choice C is the correct answer.
Why I got it wrong:
I skipped words when reading the question and focused on "lag times", a phrase I
didn't understand.
How to fix it:
Read and highlight the question carefully.
Tolazamide is an aromatic drug with a similar sulfonylurea structure to glipizide.
Which of the following is most likely tolazamide? - answer A.
Explanation:
First, it is indicated that tolazamide is an "aromatic" drug, so that eliminates choice D.
The key word is "sulfonylurea", which as the name suggests, contains sulfonyl and
urea groups.
Sulfonyl group: O=S=O
Urea group: CH4N2O
Why I got it wrong:
I didn't read the passage carefully enough to find the "sulfonylurea" clue. I also didn't
know what urea was.
How to fix it:
Carefully find the key word, "glipizide", in the passage and look for words that describe
it. Memorize structure of urea.
A student preparing for the experiments inadvertently adds an additional 400 mL of
the same acid solution to the dissolution vessel. What will be the new pOH of this
solution? - answer D. 13.0
Explanation:
, READ THE QUESTION, the answer should be pOH, which should be >7 for conc. acid,
eliminating choices A and B. When concentration remains the same, volume change
doesn't affect pH. The formula for pH is pH = -log[H]. [H] is given to be 0.1 M. Plug it
into the equation to get pH = 1, and 14 - 1 = 13 for pOH.
Why I got it wrong:
I didn't read the question carefully to see that it was asking for pOH.
How to fix it:
Read question carefully and highlight what it's asking for.
Stomach contents empty with an initial flow rate of 0.67 cm3/sec. Patients who
undergo gastric bypass surgery will increase this rate by a factor of 16. Assuming that
the flow of stomach contents approximates Poiseuille's Law, what change to their
gastrointestinal connection would explain this, provided no other changes occur that
affect stomach content flow? - answer C. The new connection radius is 2x larger.
Explanation:
According to Poiseuille's Law, Flow = ΔPπr^Lη. In this equation, ΔP is the
pressure difference across the pipe, r is the radius of the pipe, L is the length of the
pipe, and η is the viscosity of the fluid in the pipe. The question states that the flow
increased by a factor of 16. If every other variable remains constant, only 2^4 would
give 16. Thus the radius is 2.
Why I got it wrong:
I have no idea what Poiseuille's Law was.
How to fix it:
Memorize Poiseuille's Law.
When in vivo studies were performed on the three drug-polymer combinations, it was
found patients in the PolOxAemer-188 group experienced the most stomach pains
after administration. Given the results of the study, this is MOST likely due to: - answer
B. tablet fragments causing inflammation of the gastric mucosa.
Explanation:
In Figure 1, trial 3 showed the lowest percent of drug release, which shows the least
solubility. This could lead to undissolved tablet fragments, which is choice B.
Why I got it wrong:
I did not read the discussion below Figure 1, and missed the sentences about
solubility.
How to fix it:
