Question 1

Which of the following statements best explains why carboxylic acids generally have higher boiling points than aldehydes and ketones of similar molecular weight?

Accepted Answer

Carboxylic acids can form strong intermolecular hydrogen bonds, including dimerization, which significantly increases their boiling points.

Question 2

Which of the following compounds is the most water-soluble at neutral pH (pH = 7)?

Accepted Answer

Benzoic acid (as its sodium salt)

Question 3

A compound with the formula $$\mathrm{C_4H_{10}N} is $$found to be a secondary amine. Which of the following is its correct IUPAC name?

Accepted Answer

N-ethylmethanamine

Question 4

Which of the following best describes the relationship between the following two molecules?

$$\mathrm{CH_3CH_2CH(OH)CH_3$}$$ and $$\mathrm{CH_3CH(OH)CH_2CH_3}$$

Accepted Answer

They are constitutional isomers.

Question 5

Which of the following statements about the reaction of an amine with a carboxylic acid to form an amide is correct?

Accepted Answer

The reaction requires heating and often a dehydrating agent to drive off water and form the amide bond.

Question 6

Which of the following best describes the function of Tollens’ reagent in organic chemistry?

Accepted Answer

It oxidizes aldehydes to carboxylic acids, producing a silver mirror as a positive test.

Question 7

A buffer solution is prepared by mixing $$0.10\ \mathrm{mol}$$ acetic acid ($$\mathrm{p}K_a = 4.76) $$and $$0.10\ \mathrm{mol}$$ sodium acetate in $$1.0\ \mathrm{L} of $$water. What is the pH of the buffer? (Use the Henderson-Hasselbalch equation.)

Accepted Answer

$$4.76$$

Question 8

Which of the following statements about the acidity of carboxylic acids is correct?

Accepted Answer

Electron-withdrawing groups near the carboxyl group increase acidity by stabilizing the conjugate base.

Question 9

Which of the following best describes the product(s) when ethanoic acid (acetic acid) reacts with ethanol in the presence of sulfuric acid?

Accepted Answer

Ethyl acetate and water

Question 10

Which of the following molecules contains a stereocenter?

Accepted Answer

$$\mathrm{CH_3CH_2CH(OH)CH_3$} (2-$$butanol)

Question 11

Which of the following best describes the relationship between $$K_a$$ and $$pK_a$$ for a weak acid?

Accepted Answer

$$pK_a = -\log_{10} K_a$$

Question 12

Which of the following is the correct IUPAC name for the compound shown below?

$$\mathrm{CH_3CH_2COOCH_2CH_3}$$

Accepted Answer

Ethyl propanoate

Question 13

Which of the following statements about micelles is correct?

Accepted Answer

Micelles form when amphipathic molecules, such as soaps, arrange themselves with hydrophobic tails inward and hydrophilic heads outward in water.

Question 14

Which of the following best describes the process of saponification?

Accepted Answer

The base-catalyzed hydrolysis of a triglyceride to produce glycerol and soap (fatty acid salts).

Question 15

Which of the following statements about the physical properties of amides is correct?

Accepted Answer

Amides have higher boiling points than esters of similar molecular weight due to their ability to form hydrogen bonds.

Question 16

Which of the following is the correct R/S configuration for the chiral center in (S)-2-butanol?

Accepted Answer

The hydroxyl group is on the left in the Fischer projection, and the configuration is S.

Question 17

Which of the following best describes the effect of increasing the number of cis double bonds in a fatty acid on its melting point?

Accepted Answer

The melting point decreases because cis double bonds introduce kinks, preventing tight packing.

Question 18

Which of the following is the predominant form of a carboxylic acid in a solution with pH much higher than its $$pK_a$$?

Accepted Answer

The deprotonated (carboxylate) form

Question 19

Which of the following best describes the relationship between a pair of enantiomers?

Accepted Answer

They are non-superimposable mirror images of each other.

Question 20

A buffer is prepared using $$0.20\ \mathrm{mol} of a $$weak acid ($$pK_a = 5.0) $$and $$0.10\ \mathrm{mol} of $$its conjugate base in $$1.0\ \mathrm{L} of $$solution. What is the pH of the buffer? (Use the Henderson-Hasselbalch equation.)

Accepted Answer

$$4.70$$

Organic Chemistry II: Study Guide for Exam #2 – Chirality, Amines, Carbonyl Compounds, Carboxylic Acids, and Derivatives

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