Q: A proton NMR spectrum shows a triplet at 9.8 ppm. Which compound is most likely responsible for this signal?

$$\text{CH}_3\text{CH}_2\text{CH}_2\text{CHO}$$

Q: Which of the following best describes the mechanism of bromination of benzene using $$\text{Br}_2$$ and $$\text{FeBr}_3$$?

Formation of $$\text{Br}^+ as $$the electrophile, followed by electrophilic aromatic substitution

Question 1

Which of the following best describes the aromaticity of the cycloheptatrienyl cation (tropylium ion)?

Accepted Answer

It is aromatic because it has 6 π electrons and is planar.

Question 2

Given the following reaction sequence: $$	ext{Benzene} \xrightarrow{	ext{Br}_2,\ 	ext{FeBr}_3} \xrightarrow{	ext{HNO}_3,\ 	ext{H}_2	ext{SO}_4}$$, what is the major product?

Accepted Answer

m-bromonitrobenzene

Question 3

Which of the following compounds is classified as non-aromatic?

Accepted Answer

1,4-dihydroxybenzene anion (as shown in the image with NA label)

Question 4

What is the correct IUPAC name for the following compound: a cyclopentane ring with a methyl group at position 2 and an aldehyde at position 1?

Accepted Answer

2-methylcyclopentanecarbaldehyde

Question 5

Which of the following is the strongest activating group in electrophilic aromatic substitution?

Accepted Answer

$$-$$OCH_3$$

Question 6

Which of the following compounds will have the longest wavelength absorption in the UV spectrum?

Accepted Answer

A conjugated triene with the largest number of conjugated double bonds

Question 7

What is the product of the following reaction: $$	ext{tert-butanol} \xrightarrow{	ext{PCC},\ 	ext{CH}_2	ext{Cl}_2}$$?

Accepted Answer

No reaction (tert-butanol is not oxidized by PCC)

Question 8

Which of the following is a correct statement about the protonation of a neutral ketone?

Accepted Answer

The resulting species becomes more electrophilic and is activated toward nucleophilic attack.

Question 9

Which of the following is also known as a hemiacetal?

Accepted Answer

A carbon atom bonded to one -OH group, one -OR group, one alkyl group, and one hydrogen

Question 10

Which of the following compounds is least reactive in nucleophilic aromatic substitution with NaOH?

Accepted Answer

p-nitrochlorobenzene

Question 11

A proton NMR spectrum shows a triplet at 9.8 ppm. Which compound is most likely responsible for this signal?

Accepted Answer

$$	ext{CH}_3	ext{CH}_2	ext{CH}_2	ext{CHO}$$

Question 12

Which reagent can convert 3,4-dimethyl-2-pentanone to 2,3-dimethylpentane?

Accepted Answer

$$	ext{Zn(Hg)},\ 	ext{HCl}$$

Question 13

Which of the following best describes the product of the reaction: $$	ext{tert-butyl benzene} \xrightarrow{	ext{KMnO}_4,\ 	ext{NaOH},\ 	ext{heat}}$$ followed by $$	ext{dil. H}_2	ext{SO}_4$$?

Accepted Answer

Benzoic acid

Question 14

Which of the following is the correct order of reactivity for Friedel-Crafts acylation (most to least reactive)?

Accepted Answer

Benzene \u003e Toluene \u003e Nitrobenzene

Question 15

Which of the following best describes the mechanism of bromination of benzene using $$	ext{Br}_2$$ and $$	ext{FeBr}_3$$?

Accepted Answer

Formation of $$	ext{Br}^+ as $$the electrophile, followed by electrophilic aromatic substitution

Question 16

Which of the following is the major product when benzene is treated with $$	ext{Br}_2/	ext{FeBr}_3$$ followed by $$	ext{HNO}_3/	ext{H}_2	ext{SO}_4$$?

Accepted Answer

m-bromonitrobenzene

Question 17

Which of the following best describes the product of hydrolysis of a benzene ring with a tert-butyl ester group using $$	ext{HCl}/	ext{H}_2	ext{O}$$?

Accepted Answer

Benzoic acid

Question 18

Which of the following is the correct product for the oxidation of 2-methylcyclohexanol with PCC in $$	ext{CH}_2	ext{Cl}_2$$?

Accepted Answer

2-methylcyclohexanone

Question 19

Which of the following is the correct product for the reaction of benzene with $$	ext{CH}_3	ext{COCl}/	ext{AlCl}_3$$ followed by hydrolysis?

Accepted Answer

Acetophenone

Organic Chemistry Exam Study Guidance: Aromaticity, Mechanisms, and Reactions

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