Question 1

Which of the following statements best explains why the nitrogen atom in aniline ($$C_6H_5NH_2) is $$less basic than the nitrogen atom in methylamine ($$CH_3NH_2$$)?

Accepted Answer

The lone pair on nitrogen in aniline is delocalized into the aromatic ring, reducing its availability for protonation.

Question 2

Consider the following molecules: acetone ($$CH_3COCH_3) $$and phenol ($$C_6H_5OH). $$Which molecule has the more basic oxygen atom and why?

Accepted Answer

Acetone, because the oxygen is not involved in resonance with an aromatic ring and is more available for protonation.

Question 3

A cyclohexyl methyl ketone is treated with $$H_2$$ and $$Pd/C. $$What is the major product of this reaction?

Accepted Answer

Cyclohexyl methyl ketone ($$C_6H_{11}$$COCH_3$$) remains unchanged because ketones are not reduced under these conditions.

Question 4

When styrene ($$C_6H_5CH=CH_2$) is treated with aqueous $$HCl$$, what is the major organic product?

Accepted Answer

1-chloro-1-phenylethane ($$C_6H_5CHClCH_3)$$

Question 5

A tertiary alkyl halide reacts with methanol at $$30^	ext{o}C. $$What is the expected major product and the mechanism?

Accepted Answer

Tertiary alkyl methyl ether via an $$S_N1$$ mechanism.

Question 6

Which of the following best describes the stereochemical outcome of an E2 elimination of 2-bromo-1-phenylpropane?

Accepted Answer

The reaction gives a trans-alkene as the major product due to anti-periplanar geometry.

Question 7

In the addition of $$HBr to $$cyclohexene, which of the following is true regarding the formation of the product?

Accepted Answer

The reaction proceeds via a carbocation intermediate, leading to Markovnikov addition and formation of a bromocyclohexane.

Question 8

Which of the following best describes the energy profile of a two-step reaction with a rate-determining first step?

Accepted Answer

The first transition state has the highest energy, and the intermediate is lower in energy than both transition states.

Question 9

Which reagent would you use to convert benzene to a para-methylsulfonyl enantiomer as shown in the synthesis roadmap?

Accepted Answer

$$CH_3SO_2Cl$$ with $$AlCl_3$$ catalyst

Question 10

Which of the following steps is necessary to convert a primary alcohol to a carboxylic acid in a multistep synthesis?

Accepted Answer

Oxidation with $$KMnO_4 or$$ $$CrO_3$$

Question 11

In the mechanism for the addition of $$HBr to $$cyclohexene, which step is the rate-determining step?

Accepted Answer

Formation of the carbocation intermediate after protonation of the alkene.

Question 12

Which of the following is the correct order of basicity for the following nitrogen-containing compounds: pyridine, aniline, methylamine?

Accepted Answer

$$CH_3NH_2 \u003e C_5H_5N \u003e C_6H_5NH_2$$

Question 13

Which of the following best explains why the oxygen atom in acetone is more basic than the oxygen atom in phenol?

Accepted Answer

The lone pair on oxygen in acetone is not delocalized by resonance, making it more available for protonation.

Question 14

Which of the following reagents would you use to convert a bromocyclohexane to a cyclohexanol?

Accepted Answer

$$NaOH ($$aqueous)

Question 15

In a multistep synthesis, which of the following sequences would convert benzene to para-bromotoluene?

Accepted Answer

Bromination ($$Br_2$$, $$FeBr_3) $$followed by Friedel-Crafts alkylation ($$CH_3Cl$$, $$AlCl_3)$$

Question 16

Which of the following is a correct statement about the $$S_N1$$ reaction mechanism?

Accepted Answer

It involves a carbocation intermediate and is favored by polar protic solvents.

Question 17

Which of the following transformations would require the use of $$NaBH_4 as a $$reagent?

Accepted Answer

Reduction of a ketone to a secondary alcohol.

Question 18

Which of the following is the major product when 2-bromopropane is treated with $$CH_3O^- in $$methanol?

Accepted Answer

Propene ($$CH_2$$=$$CHCH_3) $$via E2 elimination.

Organic Chemistry: Practice Questions on Basicity, Elimination, Addition, and Synthesis

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