Question 1

Which of the following statements best explains why tertiary carbocations are more stable than secondary or primary carbocations?

Accepted Answer

Tertiary carbocations are stabilized by increased hyperconjugation and inductive effects from three alkyl groups.

Question 2

During the mechanism of hydrohalogenation of an alkene, which step is rate-determining?

Accepted Answer

The formation of the carbocation intermediate after the alkene attacks the proton ($$H^+).$$

Question 3

Which of the following best describes a meso compound?

Accepted Answer

A molecule with two or more stereogenic centers and a plane of symmetry, making it achiral.

Question 4

Which reaction produces an anti-Markovnikov alcohol from an alkene?

Accepted Answer

Hydroboration-oxidation

Question 5

What is the maximum number of stereoisomers possible for a molecule with three chiral centers?

Accepted Answer

$$2^3 = 8$

Question 6

Which of the following is true about the stereochemistry of hydroboration-oxidation of alkenes?

Accepted Answer

The addition of H and OH is syn, meaning both add to the same side of the double bond.

Question 7

Which of the following is NOT a characteristic step in the electron flow for ionic reactions?

Accepted Answer

Radical formation

Question 8

In the Cahn-Ingold-Prelog system, how is the configuration of a chiral center assigned as R?

Accepted Answer

If the sequence from priority 1 to 2 to 3 is clockwise when the lowest priority group is oriented away from the observer.

Question 9

Which of the following statements about Markovnikov's rule is correct?

Accepted Answer

The hydrogen atom adds to the less substituted carbon of the double bond.

Question 10

Which of the following is a structural (constitutional) isomer?

Accepted Answer

Two compounds with the same molecular formula but different connectivity of atoms.

Question 11

Which of the following best describes the difference between enantiomers and diastereomers?

Accepted Answer

Enantiomers are non-superimposable mirror images, while diastereomers are not mirror images.

Question 12

Which of the following conformations of butane is lowest in energy?

Accepted Answer

Anti conformation

Question 13

Which of the following is true about carbocation rearrangements?

Accepted Answer

They occur only if a more stable carbocation can be generated by the rearrangement.

Question 14

Which of the following is NOT a factor that stabilizes carbocations?

Accepted Answer

Steric hindrance

Question 15

A student draws a Newman projection of ethane in which the hydrogen atoms on adjacent carbons are as far apart as possible. What is the name of this conformation?

Accepted Answer

Staggered conformation

Question 16

Which of the following reactions does NOT involve a carbocation intermediate?

Accepted Answer

Hydroboration-oxidation

Question 17

Which of the following is true about the products of acid-catalyzed hydration of an unsymmetrical alkene?

Accepted Answer

A racemic mixture is formed due to planar carbocation intermediate.

Question 18

Which of the following statements about the anti conformation of butane is correct?

Accepted Answer

It is lower in energy than the gauche conformation because it avoids steric interactions between methyl groups.

Question 19

Which of the following is true about the assignment of E/Z configuration to alkenes?

Accepted Answer

E configuration is assigned when the higher priority groups are on opposite sides of the double bond.

Organic Chemistry Study Notes: Mechanisms, Alkanes, Stereochemistry, and Alkene Addition Reactions

Study Guide - Practice Questions

Study Guide - Flashcards