Question 1

Which of the following statements best describes a functional group in organic chemistry?

Accepted Answer

A group of atoms within a molecule that has a characteristic chemical behavior and reacts similarly in different molecules.

Question 2

Which of the following compounds contains a carbon–carbon double bond functional group?

Accepted Answer

Ethylene

Question 3

Which of the following is a correct example of a functional group with a carbon-oxygen double bond (carbonyl group)?

Accepted Answer

Ketone

Question 4

Why do larger alkanes have higher boiling and melting points compared to smaller alkanes?

Accepted Answer

Because dispersion forces increase as molecule size increases, requiring more energy to overcome.

Question 5

Which of the following is the general formula for alkanes?

Accepted Answer

$$\mathrm{C}_n\mathrm{H}_{2n+2}$$

Question 6

Which of the following best describes constitutional isomers?

Accepted Answer

Compounds with the same molecular formula but different connectivity of atoms.

Question 7

What is the main reason cycloalkanes are less flexible than straight-chain alkanes?

Accepted Answer

Bond rotation in cycloalkanes is restricted due to the ring structure.

Question 8

Which of the following is a correct IUPAC name for a molecule with the structure $$\mathrm{CH}_3\mathrm{CH}_2\mathrm{CH}_2\mathrm{CH}_3$$?

Accepted Answer

Butane

Question 9

Which of the following is NOT a step in the IUPAC nomenclature of alkanes?

Accepted Answer

Name the compound based on its color.

Question 10

Which of the following statements about the chair conformation of cyclohexane is correct?

Accepted Answer

It is a strain-free, three-dimensional shape that resembles a lounge chair.

Question 11

What happens to the axial and equatorial positions during a ring-flip of cyclohexane?

Accepted Answer

Axial positions become equatorial and equatorial positions become axial.

Question 12

Which of the following is a correct example of a straight-chain alkyl group?

Accepted Answer

Ethyl ($$-\mathrm{CH}_2\mathrm{CH}_3)$$

Question 13

Which of the following best describes a staggered conformation of ethane?

Accepted Answer

All C–H bonds on adjacent carbons are as far apart as possible.

Question 14

Which of the following is a functional group with carbon singly bonded to an electronegative atom?

Accepted Answer

Alcohol

Question 15

Which of the following is a correct example of a functional group with a carbon-carbon multiple bond?

Accepted Answer

Alkyne

Question 16

Which of the following is a constitutional isomer of butane ($$\mathrm{C}_4\mathrm{H}_{10}$$)?

Accepted Answer

2-Methylpropane

Question 17

Which of the following best describes the difference between a primary and a tertiary carbon atom?

Accepted Answer

A primary carbon is bonded to one other carbon, while a tertiary carbon is bonded to three other carbons.

Question 18

Which of the following is the correct reaction for the complete combustion of methane?

Accepted Answer

$$\mathrm{CH}_4 + 2\mathrm{O}_2 \rightarrow \mathrm{CO}_2 + 2\mathrm{H}_2\mathrm{O} + 890\,\mathrm{kJ}$$

Question 19

Which of the following is true about conformational isomers (conformers)?

Accepted Answer

They have the same molecular formula and connectivity but differ by rotation around single bonds.

Question 20

Which of the following is a correct example of a cycloalkane?

Accepted Answer

Cyclohexane ($$\mathrm{C}_6\mathrm{H}_{12})$$

Study Notes: Alkanes, Cycloalkanes, and Functional Groups in Organic Chemistry

Study Guide - Practice Questions