Question 1

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

Accepted Answer

$$-$$OCH_3$$

Question 2

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

Accepted Answer

p-nitrochlorobenzene

Question 3

When the carbonyl group of a neutral ketone is protonated, which of the following statements is correct?

Accepted Answer

All of the above are incorrect.

Question 4

A proton NMR spectrum of an unknown compound contains a triplet at 9.8 ppm. Which of the following could be this unknown?

Accepted Answer

$$CH_3CH_2CH_2CHO$$

Question 5

Which of the following is also known as a hemiacetal?

Accepted Answer

A compound with a carbon atom bonded to one alkoxy group ($$-OR$$), one hydroxyl group ($$-OH$$), one alkyl group, and one hydrogen.

Question 6

Which of the following trienes will have the longest wavelength absorption in UV spectra?

Accepted Answer

A triene with conjugated double bonds.

Question 7

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

Accepted Answer

$$Zn(Hg), HCl$$

Question 8

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

Accepted Answer

Aromatic

Question 9

Given the following reaction sequence:

$$	ext{Benzene} \xrightarrow{1)\ Br_2$,\ $$FeBr_3$$} \xrightarrow{2)\ $$HNO_3$$,\ H_2SO_4}$$

What is the major product?

Accepted Answer

o-bromonitrobenzene

Question 10

Which of the following best describes the aromaticity of the following compound:

$$	ext{1,4-dihydroxy-1,4-cyclohexadiene dianion}$$

Accepted Answer

Non-aromatic

Question 11

Which of the following is the correct IUPAC name for the structure below?

(Structure: 2-methylcyclopentanecarbaldehyde)

Accepted Answer

2-methylcyclopentanecarbaldehyde

Question 12

Which of the following statements about the rate-determining step in electrophilic aromatic substitution is correct?

Accepted Answer

It is the formation of the arenium ion intermediate.

Question 13

Which of the following is the correct product for the oxidation of a secondary alcohol with PCC in $$CH_2Cl_2$$?

Accepted Answer

A ketone

Question 14

Which of the following best describes the product of hydrolysis of a cyclic acetal with $$HCl/H_2O$$?

Accepted Answer

A ketone or aldehyde

Question 15

Which of the following is the major product when toluene is treated with $$SO_3/H_2SO_4$, then Cl_2$/$$AlCl_3$$, then H_2O$ and heat?

Accepted Answer

p-chlorotoluene (after desulfonation)

Question 16

Which of the following is the correct sequence of reagents to convert ethylbenzene to benzoic acid?

Accepted Answer

$$KMnO_4$$, NaOH, Heat$$ then $$dil. H_2SO_4$$

Question 17

Which of the following is the correct product for the reaction of benzaldehyde with $$CH_3CH_2MgBr$$ followed by $$H_3O^+$$?

Accepted Answer

1-phenyl-1-propanol

Question 18

Which of the following is the correct mechanism for the formation of a ketal from a ketone and an alcohol under acidic conditions?

Accepted Answer

Nucleophilic addition of alcohol to the protonated ketone, followed by loss of water and addition of a second alcohol molecule.

Aromaticity and Reaction Mechanisms in Organic Chemistry

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