Question 1

Which of the following statements best explains why hydrocarbons are generally insoluble in water?

Accepted Answer

Hydrocarbons are nonpolar molecules, while water is polar.

Question 2

Which of the following is the correct molecular formula for an alkane with 7 carbon atoms?

Accepted Answer

$$\mathrm{C_7H_{16}}$$

Question 3

A compound has the formula $$\mathrm{C_4H_{10}}. $$Which statement is true about this compound?

Accepted Answer

It can exist as two different structural isomers.

Question 4

Which property is most typical of organic compounds compared to inorganic compounds?

Accepted Answer

Low melting point

Question 5

What is the IUPAC name for the following condensed formula: $$\mathrm{CH_3CH_2CH_2CH_3}$$?

Accepted Answer

Butane

Question 6

Which of the following best describes an alkyl group?

Accepted Answer

An alkane with one hydrogen atom removed

Question 7

Which of the following is a correct example of a structural isomer?

Accepted Answer

Butane and methylpropane

Question 8

A hydrocarbon is found to have the formula $$\mathrm{C_5H_{12}}. $$Which class does it belong to?

Accepted Answer

Alkane

Question 9

Which of the following best explains why the boiling point of alkanes increases with molecular weight?

Accepted Answer

Larger molecules have greater London dispersion forces.

Question 10

Which of the following is the correct condensed formula for hexane?

Accepted Answer

$$\mathrm{CH_3CH_2CH_2CH_2CH_2CH_3}$$

Question 11

Which of the following best describes the bonding in alkanes?

Accepted Answer

Single covalent bonds between carbon atoms

Question 12

Which of the following is a property of most organic compounds?

Accepted Answer

They burn in air (are flammable).

Question 13

Which of the following is the correct IUPAC name for a three-carbon alkyl group?

Accepted Answer

Propyl

Question 14

Which of the following best describes the difference between aliphatic and aromatic hydrocarbons?

Accepted Answer

Aromatic hydrocarbons contain a benzene ring; aliphatic hydrocarbons do not.

Question 15

A compound is found to be nonpolar, has a low boiling point, and burns in air. Which type of compound is it most likely to be?

Accepted Answer

An organic compound

Question 16

Which of the following is the correct general formula for an alkane?

Accepted Answer

$$\mathrm{C_nH_{2n+2}}$$

Question 17

Which of the following is NOT a property of hydrocarbons?

Accepted Answer

High solubility in water

Question 18

Which of the following best describes a constitutional (structural) isomer?

Accepted Answer

Compounds with the same molecular formula but different connectivity of atoms

Question 19

Which of the following is the correct name for the alkyl group $$\mathrm{CH_3CH_2CH_2-}$$?

Accepted Answer

Propyl

Question 20

Which of the following best explains why gasoline (a mixture of hydrocarbons) floats on water?

Accepted Answer

Hydrocarbons are less dense than water and are nonpolar.

Introduction to Organic Chemistry: Hydrocarbons and Alkanes

Study Guide - Practice Questions