PCAT Chemistry 4

Question 1

Which functional group is present in a carboxylic acid?

Accepted Answer

-COOH

Answer

Carboxylic acids contain the -COOH functional group, which consists of both a carbonyl (C=O) and a hydroxyl (-OH) group bonded to the same carbon.

Question 2

In an SN2 reaction, which of the following substrates reacts fastest?

Accepted Answer

Primary alkyl halide

Answer

Primary alkyl halides react fastest in SN2 reactions because they have the least steric hindrance, allowing the nucleophile easy backside attack access.

Question 3

Which of the following best describes the relationship between entropy and spontaneity in the Gibbs free energy equation?

Accepted Answer

High entropy change favors spontaneity by making ΔG more negative

Answer

In ΔG = ΔH - TΔS, a large positive ΔS makes the -TΔS term more negative, thereby lowering ΔG and favoring spontaneity.

Question 4

Which of the following is an example of a nucleophile?

Accepted Answer

NH3

Answer

NH3 is a nucleophile because it has a lone pair of electrons that it can donate to electrophilic centers during a reaction.

Question 5

The pH of a 0.01 M solution of HCl is:

Accepted Answer

2

Answer

HCl is a strong acid that fully dissociates, giving [H+] = 0.01 M = 10^-2 M, so pH = -log(10^-2) = 2.

PCAT - Pharmacy College Admission Test Practice Test

PCAT - Pharmacy College Admission Test Practice Test

PCAT Chemistry 4