Question 1

Which of the following best describes the mechanism for the addition of HX to an alkene?

Accepted Answer

The reaction involves a carbocation intermediate formed after the alkene attacks the proton from HX.

Question 2

During the hydration of an alkene, which reagent is typically used to catalyze the reaction?

Accepted Answer

A dilute acid such as H$$_2SO$_4$$

Question 3

Which product is expected from the hydrohalogenation of 2-methylpropene with HBr, considering Markovnikov's rule?

Accepted Answer

2-bromo-2-methylpropane

Question 4

What is the major product when 1-butene reacts with Br$$_2 in $$CCl$$_4$$?

Accepted Answer

1,2-dibromobutane

Question 5

Which of the following best explains why the addition of HBr to 1,3-butadiene at low temperature yields mainly 1,2-addition product?

Accepted Answer

The reaction is under kinetic control, favoring the fastest-forming product.

Question 6

Which reagent is commonly used for the syn-dihydroxylation of alkenes?

Accepted Answer

KMnO$$_4 ($$cold, dilute)

Question 7

In the ozonolysis of cyclohexene, which products are formed after reductive workup with Zn/AcOH?

Accepted Answer

Adipaldehyde (hexane-1,6-dial)

Question 8

Which of the following is a characteristic of E2 elimination reactions?

Accepted Answer

The reaction requires anti-periplanar geometry between the leaving group and the hydrogen.

Question 9

Which statement best describes the regioselectivity of electrophilic aromatic substitution?

Accepted Answer

Electron-donating groups direct substitution to the ortho and para positions.

Question 10

What is the expected product when benzene reacts with acetyl chloride (CH$$_3$$COCl) in the presence of AlCl$$_3$$?

Accepted Answer

Acetophenone

Question 11

Which of the following is true about the mechanism of nucleophilic aromatic substitution?

Accepted Answer

It requires a strong nucleophile and an electron-withdrawing group ortho or para to the leaving group.

Question 12

Which of the following reactions is used to convert an alkene to a vicinal diol?

Accepted Answer

Cold, dilute KMnO$$_4$$

Question 13

Which product is formed when 1-butyne undergoes hydroboration-oxidation?

Accepted Answer

Butanal (from anti-Markovnikov addition)

Question 14

Which of the following is a key feature of the Friedel-Crafts alkylation reaction?

Accepted Answer

It can lead to polyalkylation if excess alkyl halide is used.

Question 15

Which reagent is used for the oxidative cleavage of alkenes to form carboxylic acids and/or ketones?

Accepted Answer

Hot, concentrated KMnO$$_4$$

Question 16

What is the major product when ethylbenzene undergoes bromination under radical conditions?

Accepted Answer

1-bromo-1-phenylethane

Question 17

Which of the following best describes the outcome of the E1 elimination reaction of 2-butanol in acidic conditions?

Accepted Answer

The major product is 2-butene due to Zaitsev's rule.

Question 18

Which of the following is true about the anti-Markovnikov addition of HBr to alkenes?

Accepted Answer

It requires the presence of peroxides to proceed.

Question 19

Which of the following is a product of the reaction between benzene and methyl chloride (CH$$_3Cl) in $$the presence of AlCl$$_3$$?

Accepted Answer

Toluene

Question 20

Which of the following is a correct statement about the formation of halohydrins from alkenes?

Accepted Answer

The reaction involves the addition of a halogen and water across the double bond.

Key Organic Reaction Mechanisms for Final Exam (Chapters 13, 14, 18)

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