Question 1

Which of the following statements best explains why carbon is the central element in organic chemistry?

Accepted Answer

Carbon can form long chains and single, double, and triple bonds, allowing for a diverse array of molecules.

Question 2

What is the molecular formula for a non-cyclic alkane with 7 carbon atoms?

Accepted Answer

$\mathrm{C_7H_{16}}$

Question 3

Which of the following is NOT a functional group commonly found in organic molecules?

Accepted Answer

Methane ($CH_4$)

Question 4

A molecule with the formula $\mathrm{C_4H_8}$ could be which type of hydrocarbon?

Accepted Answer

A cyclic alkane

Question 5

Which Greek prefix is used for an organic molecule containing 9 carbon atoms?

Accepted Answer

non

Question 6

Which representation of an organic molecule provides the most information about atomic connectivity and electron pairs?

Accepted Answer

Lewis (structural) structure

Question 7

What is the main difference between alkanes and alkenes?

Accepted Answer

Alkanes contain only single bonds, while alkenes contain at least one double bond.

Question 8

Which of the following molecules is aromatic?

Accepted Answer

Benzene

Question 9

What is the hybridization of carbon atoms in alkanes?

Accepted Answer

$sp^3$

Question 10

Which of the following best describes a constitutional isomer?

Accepted Answer

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

Question 11

A student draws a bond-line structure and omits all hydrogen atoms attached to carbon. What is the main advantage of this representation?

Accepted Answer

It simplifies large molecules and highlights the carbon framework.

Question 12

Which notation is used to indicate a bond going into the page in three-dimensional bond-line structures?

Accepted Answer

Dash

Question 13

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

Accepted Answer

$\mathrm{C_5H_{10}}$

Question 14

Which of the following molecules contains a triple bond?

Accepted Answer

Ethyne

Question 15

Which type of isomerism involves molecules with the same connectivity but different spatial arrangement?

Accepted Answer

Configurational isomerism

Question 16

Which of the following is an example of an aliphatic compound?

Accepted Answer

Hexane

Question 17

A pharmaceutical molecule contains a benzene ring and a carboxyl group. Which category does it belong to?

Accepted Answer

Aromatic

Question 18

Which of the following best describes the difference between saturated and unsaturated hydrocarbons?

Accepted Answer

Saturated hydrocarbons contain only single bonds, while unsaturated hydrocarbons contain double or triple bonds.

Question 19

Which of the following is the correct condensed structural formula for diethyl ether?

Accepted Answer

$\mathrm{CH_3CH_2OCH_2CH_3}$

Question 20

Which of the following is a real-world example of an organic compound that contains a functional group responsible for its reactivity?

Accepted Answer

Ethanol, which contains a hydroxyl group ($-OH$) responsible for its solubility and reactivity.

Organic Chemistry I – Structures: Hydrocarbons and Functional Groups

Study Guide - Practice Questions