$$\text{CH}_2=\text{C}(\text{O}^\text{–})\text{CH}_3$$

Loss of a tert-butyl cation ($$\text{C}_4\text{H}_9^+)$$

Question 1

Which of the following best describes the criteria for aromaticity according to Hückel's rule?

Accepted Answer

A molecule must be cyclic, planar, fully conjugated, and contain $$(4n+2)$$ $$	ext{π}$$ electrons.

Question 2

Which spectroscopic technique is most useful for determining the number and types of hydrogen atoms in an organic molecule?

Accepted Answer

Proton nuclear magnetic resonance ($$^1H $$NMR) spectroscopy

Question 3

In electrophilic aromatic substitution, which step is rate-determining?

Accepted Answer

Formation of the carbocation intermediate (arenium ion)

Question 4

Which functional group is most reactive towards nucleophilic addition reactions?

Accepted Answer

Aldehyde

Question 5

A compound gives a strong absorption at $$1700 cm$^{-1} in $$its IR spectrum. Which functional group is most likely present?

Accepted Answer

Carbonyl (C=O)

Question 6

Which of the following statements about organometallic compounds is correct?

Accepted Answer

Grignard reagents react with carbonyl compounds to form alcohols.

Question 7

Which of the following is a correct mechanism for the formation of an acetal from an aldehyde?

Accepted Answer

Nucleophilic addition of alcohol followed by elimination of water.

Question 8

Which compound would show a singlet at $$	ext{δ} = 2.1$$ ppm in its $$^1H $$NMR spectrum, corresponding to three protons?

Accepted Answer

Acetone

Question 9

Which of the following is true about nucleophilic aromatic substitution?

Accepted Answer

It is favored by electron-withdrawing groups on the aromatic ring.

Question 10

A student reacts benzaldehyde with sodium hydroxide and ethanol. Which product is most likely formed?

Accepted Answer

Benzalcohol (via aldol condensation)

Question 11

Which of the following best explains why phenol is more acidic than cyclohexanol?

Accepted Answer

Phenol's conjugate base is stabilized by resonance.

Question 12

Which of the following is the correct formula for the enolate ion formed from acetone?

Accepted Answer

$$	ext{CH}_2=	ext{C}(	ext{O}^	ext{–})	ext{CH}_3$$

Question 13

Which of the following is a typical product of the reaction between a carboxylic acid and an alcohol in the presence of acid?

Accepted Answer

Ester

Question 14

Which of the following best describes the fragmentation pattern in mass spectrometry for a compound containing a tert-butyl group?

Accepted Answer

Loss of a tert-butyl cation ($$	ext{C}_4	ext{H}_9^+)$$

Question 15

Which of the following is the correct order of reactivity for carboxylic acid derivatives towards nucleophilic acyl substitution?

Accepted Answer

Acid chloride \u003e Anhydride \u003e Ester \u003e Amide

Question 16

Which of the following statements about ethers is correct?

Accepted Answer

Ethers are generally unreactive and used as solvents.

Question 17

Which of the following is a correct description of the $$^{13}C $$NMR spectrum of benzene?

Accepted Answer

Six equivalent carbon signals at $$\delta = 128$$ ppm.

Question 18

Which of the following is the major product when acetophenone is treated with bromine in acetic acid?

Accepted Answer

Bromination at the para position of the aromatic ring

Question 19

Which of the following is a correct statement about the use of curved arrows in organic reaction mechanisms?

Accepted Answer

Curved arrows show the movement of electrons during a reaction.

Organic Chemistry II (CHM 304) Syllabus and Course Structure – Medgar Evers College

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