Chemistry Flashcards
7 cards from real PCAT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Chemistry flashcards as text
Which functional group is present in a carboxylic acid?
Answer: -COOH
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.
In an SN2 reaction, which of the following substrates reacts fastest?
Answer: Primary alkyl halide
Primary alkyl halides react fastest in SN2 reactions because they have the least steric hindrance, allowing the nucleophile easy backside attack access.
Which of the following best describes the relationship between entropy and spontaneity in the Gibbs free energy equation?
Answer: High entropy change favors spontaneity by making ΔG more negative
In ΔG = ΔH - TΔS, a large positive ΔS makes the -TΔS term more negative, thereby lowering ΔG and favoring spontaneity.
Which of the following is an example of a nucleophile?
Answer: NH3
NH3 is a nucleophile because it has a lone pair of electrons that it can donate to electrophilic centers during a reaction.
The pH of a 0.01 M solution of HCl is:
Answer: 2
HCl is a strong acid that fully dissociates, giving [H+] = 0.01 M = 10^-2 M, so pH = -log(10^-2) = 2.
The Aufbau principle states that electrons:
Answer: Fill lower energy orbitals before higher ones
The Aufbau principle states that electrons fill available orbitals starting with those of lowest energy, building up the electron configuration from the ground state.
Which of the following reactions represents saponification?
Answer: Hydrolysis of an ester in basic conditions to form a carboxylate salt and alcohol
Saponification is the base-catalyzed hydrolysis of an ester, producing a carboxylate salt and alcohol, commonly used in soap-making.