Question 1

Which of the following statements about bond-line structures is TRUE?

Accepted Answer

Heteroatoms and the hydrogens attached to them must be shown in bond-line structures.

Question 2

A carbon atom in a bond-line structure is shown with only three bonds and no lone pairs. What is its formal charge?

Accepted Answer

+1

Question 3

Which of the following is NOT a valid use of curved arrows when drawing resonance structures?

Accepted Answer

Breaking a sigma bond to form a lone pair.

Question 4

Which rule is MOST important when determining the major resonance contributor for a molecule?

Accepted Answer

The structure with the greatest number of filled octets.

Question 5

Consider the molecule $CH_3CH_2OH$. Which functional group does it contain?

Accepted Answer

Alcohol

Question 6

Which of the following best describes a resonance hybrid?

Accepted Answer

A single structure that averages the features of all significant resonance contributors.

Question 7

In the allyl carbocation, how are the positive charge and pi electrons distributed?

Accepted Answer

The pi electrons and positive charge are delocalized over three carbon atoms.

Question 8

Which of the following patterns does NOT typically lead to resonance?

Accepted Answer

A sigma bond between two atoms of similar electronegativity

Question 9

A nitrogen atom in a molecule has three bonds and one lone pair. What is its formal charge?

Accepted Answer

0

Question 10

Which of the following statements about delocalized and localized lone pairs is CORRECT?

Accepted Answer

Delocalized lone pairs are adjacent to atoms with unhybridized p orbitals.

Question 11

Which of the following is a correct application of the octet rule in resonance structures for second-row elements?

Accepted Answer

Second-row elements can have less than eight electrons, but never more.

Question 12

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

Accepted Answer

$CH_3CH(OH)CH_3$

Question 13

When converting a Lewis structure to a bond-line structure, which of the following is NOT necessary?

Accepted Answer

Drawing all carbon atoms explicitly.

Question 14

Which of the following best explains why resonance stabilizes a molecule?

Accepted Answer

Delocalization of electrons lowers energy by spreading out charge and minimizing electron repulsion.

Question 15

Which of the following is a valid resonance structure for the acetate ion ($CH_3COO^-$)?

Accepted Answer

Both oxygen atoms share the negative charge equally through delocalization.

Question 16

Which of the following is the most significant resonance contributor for a molecule with a negative charge?

Accepted Answer

The structure with the negative charge on the most electronegative atom.

Question 17

Which of the following is TRUE about the use of wedges and dashes in molecular drawings?

Accepted Answer

Solid wedges indicate bonds coming out of the plane of the paper.

Question 18

Which of the following molecules contains a conjugated system suitable for resonance?

Accepted Answer

Benzene

Question 19

Which of the following is NOT a functional group?

Accepted Answer

Carbocation

Question 20

Which of the following statements about resonance structures is FALSE?

Accepted Answer

Resonance structures switch back and forth rapidly in reality.

Organic Chemistry Chapter 2: Molecular Representations – Study Notes

Study Guide - Practice Questions