Question 1

Which of the following statements best describes the difference between alkanes, alkenes, and alkynes?

Accepted Answer

Alkanes contain only single bonds, alkenes contain at least one double bond, and alkynes contain at least one triple bond.

Question 2

What is the molecular formula for hexane?

Accepted Answer

$$\mathrm{C_6H_{14}}$$

Question 3

Which of the following is the correct IUPAC name for the compound with the structure $$\mathrm{CH_3CH_2CH(CH_3$)CH_2CH_3}$$?

Accepted Answer

2-Methylpentane

Question 4

Which conformation of ethane is the most stable and why?

Accepted Answer

Staggered, because it minimizes electron repulsion between hydrogen atoms.

Question 5

What is the hybridization of the carbon atoms in ethyne (acetylene)?

Accepted Answer

$$sp$$

Question 6

Which of the following best describes the geometry around each carbon atom in ethene ($$\mathrm{C_2H_4}$$)?

Accepted Answer

Trigonal planar, with bond angles of approximately $$120^\circ$$

Question 7

Which of the following is a correct example of a cis-trans (E/Z) isomerism in alkenes?

Accepted Answer

2-Butene ($$\mathrm{CH_3CH=$$CHCH_3$$}) $$can exist as both cis and trans isomers.

Question 8

Which of the following reactions is an example of an addition reaction?

Accepted Answer

$$\mathrm{CH_2$=CH_2$ + HCl \rightarrow CH_3CH_2Cl}$$

Question 9

Which of the following statements about cyclohexane conformations is correct?

Accepted Answer

The chair conformation is more stable than the boat conformation due to minimized steric strain.

Question 10

Which of the following is the correct order of priority for substituents when assigning E/Z configuration to alkenes?

Accepted Answer

Br \u003e Cl \u003e S \u003e P \u003e O \u003e N \u003e C \u003e H

Question 11

Which of the following is a correct example of a nucleophile in organic reaction mechanisms?

Accepted Answer

Hydroxide ion ($$\mathrm{OH^-})$$

Question 12

In the reaction mechanism for the addition of HCl to ethene, what is the first step?

Accepted Answer

Formation of a carbocation intermediate by electrophilic attack of HCl on ethene.

Question 13

Which of the following best describes the difference between symmetrical and unsymmetrical bond breaking?

Accepted Answer

Symmetrical bond breaking produces two radicals, while unsymmetrical bond breaking produces ions.

Question 14

Which of the following is the correct systematic name for the compound with the structure $$\mathrm{CH_3CH_2C\equiv $$CCH_3$$}$$?

Accepted Answer

2-Pentyne

Question 15

Which of the following is a correct example of a substitution reaction?

Accepted Answer

$$\mathrm{CH_4$ + Cl_2$ \rightarrow CH_3Cl + HCl}$$

Question 16

Which of the following is the correct condensed structural formula for isobutane?

Accepted Answer

$$\mathrm{(CH_3$)_3CH}$$

Question 17

Which of the following best explains why trans-2-butene is more stable than cis-2-butene?

Accepted Answer

Trans-2-butene has less steric strain between methyl groups than cis-2-butene.

Question 18

Which of the following is the correct IUPAC name for the compound with the structure $$\mathrm{CH_3CH_2CH_2CH_2CH_3}$$?

Accepted Answer

Pentane

Question 19

Which of the following statements about the Newman projection of ethane is correct?

Accepted Answer

The staggered conformation has lower energy than the eclipsed conformation.

Organic Chemistry Fundamentals: Alkanes, Alkenes, Alkynes, and Reaction Mechanisms

Study Guide - Practice Questions