Question 1

Which of the following statements best describes a skeletal structure in organic chemistry?

Accepted Answer

It shows bonds between carbon atoms as lines, omits hydrogen atoms bonded to carbon, and displays other atoms using their symbols.

Question 2

What is the general molecular formula for straight-chain alkanes?

Accepted Answer

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

Question 3

Which of the following is NOT a correct rule for drawing skeletal structures?

Accepted Answer

Lone pairs of electrons are shown explicitly.

Question 4

Which of the following best describes a saturated hydrocarbon?

Accepted Answer

A compound containing only single bonds between carbon atoms and the maximum number of hydrogen atoms.

Question 5

Which of the following is the correct IUPAC name for a straight-chain alkane with six carbon atoms?

Accepted Answer

Hexane

Question 6

Which statement about alkanes is TRUE?

Accepted Answer

Alkanes are nonpolar and do not dissolve well in water.

Question 7

What is the product of the complete combustion of an alkane?

Accepted Answer

Carbon dioxide and water

Question 8

Which of the following is a correct description of a functional group in organic chemistry?

Accepted Answer

A group of atoms that determines the reactivity and properties of an organic molecule.

Question 9

Which of the following is a hydrocarbon functional group that contains a carbon-carbon triple bond?

Accepted Answer

Alkyne

Question 10

Which statement about cis-trans isomerism in alkenes is correct?

Accepted Answer

Cis-trans isomerism occurs when each alkene carbon has two different groups attached.

Question 11

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

Accepted Answer

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

Question 12

Which of the following is TRUE about chiral centers in organic molecules?

Accepted Answer

A chiral center is a carbon atom bonded to four different atoms or groups.

Question 13

Which of the following best explains why benzene is unusually stable?

Accepted Answer

The electrons in the double bonds are shared evenly among the six carbons in a resonance hybrid.

Question 14

Which of the following is a correct IUPAC rule for naming branched-chain alkanes?

Accepted Answer

List substituents in alphabetical order at the beginning of the name.

Question 15

Which of the following statements about fatty acids is correct?

Accepted Answer

Polyunsaturated fatty acids contain two or more double bonds.

Question 16

Which of the following is a consequence of chirality in pharmaceuticals?

Accepted Answer

Only one enantiomer may be biologically active, while the other can be inactive or harmful.

Question 17

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

Accepted Answer

$$\mathrm{CH}_3\mathrm{CH}_2\mathrm{CH}_2\mathrm{CH}_3$$

Question 18

Which of the following is a correct description of a conformational isomer?

Accepted Answer

Different arrangements of the same molecule due to rotation around single bonds.

Question 19

Which of the following is a correct statement about cycloalkanes?

Accepted Answer

Cycloalkanes are ring-form alkanes named by adding the prefix 'cyclo' to the alkane name.

Question 20

Which of the following is the correct molecular formula for cyclopentane?

Accepted Answer

$$\mathrm{C}_5\mathrm{H}_{10}$$

Introduction to Organic Compounds: Structure Representation

Study Guide - Practice Questions