Question 1

Which of the following is a correct set of structural isomers for the molecular formula $$\mathrm{C_3H_7F}$$?

Accepted Answer

1-fluoropropane and 2-fluoropropane

Question 2

What is the correct formal charge on the nitrogen atom in the following structure?

$$\mathrm{H_2N{-}NH_2$}$$

Accepted Answer

Both nitrogens have a formal charge of $$0$$

Question 3

Which of the following best describes the electron flow in the resonance structure of the acetate ion ($$\mathrm{CH_3CO_2^-}$$)?

Accepted Answer

A lone pair from one oxygen forms a double bond with carbon, while the double bond to the other oxygen becomes a lone pair.

Question 4

In the structure of cocaine, which functional group is indicated by an arrow pointing to the $$\mathrm{$$COOCH_3$$}$$ group?

Accepted Answer

Ester

Question 5

What is the correct IUPAC name for the following structure?

A seven-carbon chain with an ethyl group at C4 and two methyl groups at C2.

Accepted Answer

4-ethyl-2,2-dimethylheptane

Question 6

Which of the following best describes the stereochemical configuration of the double bond in 2-butene when the two methyl groups are on the same side?

Accepted Answer

cis

Question 7

When drawing the two staggered conformations of butane, which conformation is more stable and why?

Accepted Answer

The anti conformation is more stable because the two methyl groups are $$180^\circ$$ apart, minimizing steric hindrance.

Question 8

Which of the following statements about the two eclipsed conformations of butane is correct?

Accepted Answer

The conformation where the two methyl groups are eclipsed is less stable due to greater steric strain.

Question 9

For trans-1-tert-butyl-4-methylcyclohexane, which chair conformation is more stable?

Accepted Answer

The conformation where the tert-butyl group is equatorial and the methyl group is axial.

Question 10

Which of the following best describes the product of the acid-catalyzed hydration of 2-methyl-2-butene?

Accepted Answer

2-methyl-2-butanol as the major product, following Markovnikov addition

Question 11

Classify the following carbocation: $$\mathrm{Ph{-}C^+H_2$} (a $$benzyl carbocation).

Accepted Answer

Primary (1°)

Question 12

In the reaction of 1-butene with HBr, what is the major product and why?

Accepted Answer

2-bromobutane, due to Markovnikov addition

Question 13

Which of the following best explains why the anti-Markovnikov product is not observed in the reaction of 1-butene with HBr under cold conditions?

Accepted Answer

Peroxides are not present to initiate a radical mechanism.

Question 14

Which of the following bases would be most effective at deprotonating HCN ($$\mathrm{p}K_a \approx 10$$)?

Accepted Answer

Sodium amide ($$\mathrm{$$NaNH_2$$}$$, $$\mathrm{p}K_a of $$conjugate acid $$\approx 35)$$

Question 15

Write the balanced equation for the deprotonation of HCN by sodium amide. Which species are the acid, base, conjugate acid, and conjugate base?

Accepted Answer

$$\mathrm{HCN + NH_2$^- \rightarrow CN^- + NH_3$}$$; HCN is the acid, $$\mathrm{NH_2$^-} is $$the base, $$\mathrm{CN^-} is $$the conjugate base, $$\mathrm{NH_3$} is $$the conjugate acid.

Question 16

Which of the following best explains why compound C (1,4-dibromobutane) is formed as a minor product in the reaction of 1-butene with HBr, while compound B (2,2-dibromobutane) is not observed?

Accepted Answer

A carbocation rearrangement leads to the formation of compound C, while B is not formed due to the instability of a secondary carbocation.

Question 17

Which of the following is the correct mechanism for the acid-catalyzed hydration of 1-butene?

Accepted Answer

Protonation of the double bond to form a carbocation, followed by nucleophilic attack by water and deprotonation to yield 2-butanol.

Organic Chemistry I: Key Concepts and Problem Types (Exam Study Guide)

Guida di studio - Domande di pratica

Study guide - Flashcard