Question 1

Which of the following statements best describes a resonance structure?

Accepted Answer

A structure that shows the movement of electrons from either a double bond or lone pair.

Question 2

How many double bonds must a polyatomic species possess to have valid Lewis Dot resonance structures?

Accepted Answer

At least 1 double bond

Question 3

In a resonance structure, what is moved between atoms?

Accepted Answer

Electrons

Question 4

What does a double-sided arrow ($\leftrightarrow$) indicate between two Lewis structures?

Accepted Answer

The structures are equivalent resonance forms.

Question 5

What is the term for the actual structure of a molecule that is a composite of all resonance structures?

Accepted Answer

Resonance hybrid

Question 6

When drawing a resonance hybrid, how should a delocalized bond be represented?

Accepted Answer

With a dotted line

Question 7

Which of the following is a correct resonance structure for the carbonate ion ($\mathrm{CO_3^{2-}}$)?

Accepted Answer

A structure with one double bond and two single bonds, with the double bond rotating among the three oxygens.

Question 8

Which statement about resonance structures is FALSE?

Accepted Answer

Resonance structures show the movement of atoms.

Question 9

For the phosphate ion ($\mathrm{PO_4^{3-}}$), how many resonance structures are possible?

Accepted Answer

4

Question 10

Which of the following best explains why resonance structures are important in chemistry?

Accepted Answer

They help predict the reactivity and stability of molecules by showing electron delocalization.

Question 11

Given the nitrate ion ($\mathrm{NO_3^-}$), which of the following is true about its resonance structures?

Accepted Answer

There are three equivalent resonance structures.

Question 12

Which of the following ions does NOT have resonance structures?

Accepted Answer

$\mathrm{NH_4^+}$

Question 13

A student draws a resonance structure for $\mathrm{NO_2^-}$ with both oxygens having double bonds to nitrogen. What is the error in this structure?

Accepted Answer

It violates the octet rule for nitrogen.

Question 14

Which of the following is the correct way to represent the resonance hybrid of $\mathrm{CO_3^{2-}}$?

Accepted Answer

Draw a single structure with dotted lines for the bonds between carbon and oxygen.

Question 15

Which of the following best describes the relationship between resonance structures and the actual molecule?

Accepted Answer

The actual molecule is a blend (hybrid) of all resonance structures.

Question 16

Which of the following is a common misconception about resonance structures?

Accepted Answer

Resonance structures represent different molecules.

Question 17

Which of the following ions has the greatest number of resonance structures?

Accepted Answer

$\mathrm{PO_4^{3-}}$

Question 18

Which of the following is the correct charge for the phosphate ion in its resonance structures?

Accepted Answer

$3-$

Question 19

In the context of resonance, what does the term 'delocalization' refer to?

Accepted Answer

The spreading of electrons over several atoms, rather than being localized between two atoms.

Question 20

Which of the following best describes the use of resonance structures in predicting chemical reactivity?

Accepted Answer

Resonance structures help identify regions of high electron density, which are likely sites for chemical reactions.

Resonance Structures and Resonance Hybrids in Polyatomic Ions

Study Guide - Practice Questions