Question 1

Which statement best explains why carbon is able to form such a wide variety of organic molecules?

Accepted Answer

Carbon is tetravalent and can form four covalent bonds, allowing for complex structures.

Question 2

What is the molecular geometry around a carbon atom with three groups attached, such as in ethylene ($\mathrm{C_2H_4}$)?

Accepted Answer

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

Question 3

Which of the following molecules is most likely to be soluble in water?

Accepted Answer

A small molecule with several polar functional groups

Question 4

Which functional group is present in the following condensed formula: $\mathrm{CH_3CH_2OH}$?

Accepted Answer

Alcohol

Question 5

A carbon atom forms a double bond with oxygen and is at the end of a chain. Which functional group does this describe?

Accepted Answer

Aldehyde

Question 6

Which of the following line structures represents butane?

Accepted Answer

A four-carbon straight chain with no branches

Question 7

What is the general formula for alkanes?

Accepted Answer

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

Question 8

Which of the following is a constitutional (structural) isomer of $\mathrm{C_4H_{10}}$?

Accepted Answer

2-methylpropane

Question 9

A molecule contains a carbon atom bonded to a nitrogen atom and a double-bonded oxygen atom on the same carbon. Which functional group is this?

Accepted Answer

Amide

Question 10

Which of the following best describes the difference between conformers and constitutional isomers?

Accepted Answer

Conformers differ by rotation around single bonds, while constitutional isomers differ in atom connectivity.

Question 11

Which of the following condensed formulas corresponds to a molecule with a triple bond between two carbons?

Accepted Answer

$\mathrm{CH\equiv CCH_3}$

Question 12

Which of the following best explains why most organic molecules are nonpolar?

Accepted Answer

They are composed mostly of carbon and hydrogen, which have similar electronegativities.

Question 13

Which of the following is NOT a correct guideline for drawing line structures of organic molecules?

Accepted Answer

Every carbon atom must be shown with all four bonds explicitly drawn.

Question 14

A molecule with the formula $\mathrm{C_3H_8O}$ could be which of the following?

Accepted Answer

An alcohol or an ether

Question 15

Which of the following functional groups is characterized by a sulfur atom bonded to a hydrogen atom at the end of a chain?

Accepted Answer

Thiol

Question 16

Which of the following molecules contains a polar covalent bond?

Accepted Answer

$\mathrm{CCl_4}$

Question 17

Which of the following is a correct condensed formula for 2-methylpropane?

Accepted Answer

$\mathrm{CH_3CH(CH_3)CH_3}$

Question 18

Which of the following statements about functional groups is TRUE?

Accepted Answer

The chemistry of an organic molecule is primarily defined by the functional groups it contains.

Question 19

Which of the following is a correct line structure for pentane?

Accepted Answer

A five-carbon straight chain with no branches

Question 20

Which of the following molecules is a conformer of butane?

Accepted Answer

A molecule with the same connectivity but different rotation around a C-C bond

Structure and Classification of Organic Molecules

Study Guide - Practice Questions