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

Which molecule has the most basic oxygen atom?

Accepted Answer

Methoxide ion ($$CH_3O^-)$$

Question 3

A cyclohexyl methyl group is hydrogenated with $$H_2$$, Pd/C. What is the major product?

Accepted Answer

Methylcyclohexane ($$C_6H_{11}CH_3$)

Question 4

When 1-phenyl-1-propene reacts with HCl (excess), what is the major organic product?

Accepted Answer

1,1-dichloro-1-phenylpropane

Question 5

A stereoselective E2 elimination of 1-bromo-1-phenylpropane yields which major product?

Accepted Answer

$$C_6H_5CH=$$CHCH_3$$ (trans-1-phenyl-1-propene)

Question 6

Which of the following best describes the mechanism for the addition of HBr to cyclohexene to form bromocyclohexane?

Accepted Answer

Electrophilic addition via a carbocation intermediate

Question 7

In the reaction-energy profile for the addition of HBr to cyclohexene, what does the highest point on the curve represent?

Accepted Answer

The transition state of the rate-determining step

Question 8

Which reagent would you use to convert benzene to the target molecule $$C_6H_5CH_2CH_2CH_3 (n-$$propylbenzene)?

Accepted Answer

Propyl chloride and AlCl$$_3 ($$Friedel-Crafts alkylation)

Question 9

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

Accepted Answer

Methylamine \u003e Pyridine \u003e Aniline

Question 10

Which of the following best explains why the methoxide ion ($$CH_3O^-) is a $$stronger base than ethanol ($$CH_3CH_2OH$$)?

Accepted Answer

Methoxide ion has a negative charge, making its lone pair more available for protonation.

Question 11

Which of the following is the major product when 2-methyl-2-butene reacts with methanol at 30°C?

Accepted Answer

2-methoxy-2-methylbutane

Question 12

In a multi-step synthesis, which sequence of reagents would convert benzene to p-bromonitrobenzene?

Accepted Answer

1) HNO$$_3$$, H$$_2SO$_4$$; 2) Br$$_2$$, FeBr$$_3$$

Question 13

Which of the following best describes the stereochemistry of the product formed in the E2 elimination of 2-bromo-3-methylpentane?

Accepted Answer

The major product is the more substituted (Zaitsev) alkene with trans geometry.

Question 14

Which of the following is a correct statement about the rate-determining step in a multi-step reaction?

Accepted Answer

It has the highest activation energy ($$\Delta G$$^{\ddagger}$$) among all steps.

Question 15

In the synthesis roadmap, which reagent is required to convert a primary alcohol to an aldehyde?

Accepted Answer

PCC (Pyridinium chlorochromate)

Question 16

Which of the following transformations would require the use of $$Br_2$$, hv (light)?

Accepted Answer

Allylic bromination of cyclohexene

Question 17

Which of the following is the correct structure for the product of the reaction: $$C_6H_5CH_2CH=CH_2$ + HCl (excess)?

Accepted Answer

$$C_6H_5CH_2CHClCH_2Cl$$

Question 18

Which of the following best describes the electron flow in the mechanism for the addition of HBr to an alkene?

Accepted Answer

The alkene pi electrons attack the proton of HBr, forming a carbocation intermediate.

Question 19

Which of the following is the correct order of reactivity for the following alkyl halides in an E2 elimination: 1-bromopropane, 2-bromopropane, 2-bromo-2-methylpropane?

Accepted Answer

2-bromo-2-methylpropane \u003e 2-bromopropane \u003e 1-bromopropane

Organic Chemistry: Basicity, Elimination, Reaction Mechanisms, and Synthesis

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