# Step-by-Step Solution ## 1. **Identify the Structure and Positive Charge** The structure is an **imidazole ring** with a positive charge on the nitrogen atom at the top. The group labeled \( R \) is not involved in resonance. ``` N^+ / \ N--C C==R || / C----N ``` - \( N^+ \) is the protonated nitrogen (has a positive charge). - The rest are standard imidazole atoms. --- ## 2. **Draw Possible Resonance Structures** ### **Structure 1: Starting Structure** - The positive charge is on the top nitrogen (\(N^+\)): ``` N^+ / \ N--C C==R || / C----N ``` ### **Structure 2: Move Double Bond and Charge** Move the double bond from the bottom C=N to the N at the right, shifting the positive charge to the bottom N: 1. Move the lone pair from the bottom N to form a double bond with the bottom C. 2. Move the bottom C=N double bond's electrons up to neutralize the positive charge on the top N, shifting the positive charge to the bottom N. ``` N / \ N--C C==R || / C^+---N ``` - Now the positive charge is on the bottom N. ### **Structure 3: Move Bond Again** Move the double bond again, so the positive charge is now on the left N: 1. Move the lone pair from the left N to form a double bond with the left C. 2. Move the electrons from the double bond between the bottom N and bottom C to the bottom N. ``` N / \ N^+==C C==R | / C----N ``` - Now the positive charge is on the left N. --- ## 3. **Draw the Resonance Hybrid** The **resonance hybrid** will show: - Partial positive charge delocalized over the three nitrogens. - Dashed bonds where double bonds are delocalized. ``` N / \ N--C C==R || / C----N ``` - Draw dashed lines for bonds that are partially double. - Draw a \( \delta^+ \) (partial positive) on each nitrogen involved in delocalization. --- ## 4. **Label Final Answers** ### **Resonance Structures** #### **Structure 1**  - Positive charge on the top N. #### **Structure 2**  - Positive charge on the bottom N. #### **Structure 3**  - Positive charge on the left N. ### **Resonance Hybrid**  - Dashed lines indicate delocalization. - Partial positive charges shown on the three nitrogens. --- ## **Summary Table** | Structure | Positive Charge Location | |-------------|-------------------------| | 1 | Top N | | 2 | Bottom N | | 3 | Left N | --- ## **Final Answer** **All three resonance structures must be drawn, with the positive charge delocalized over the three nitrogen atoms. The resonance hybrid shows dashed bonds and partial positive charges over all three nitrogens.**

# Step-by-Step Solution ## 1. Identify the Structure and Positive Charge The molecule in question features an **imidazole ring** with a positive charge on one of the nitrogen atoms. The group labeled \( R \) is not involved in resonance. ### Structure Representation ``` N^+ / \ N--C C==R || / C----N ``` - **\( N^+ \)**: Protonated nitrogen with a positive charge. --- ## 2. Draw Possible Resonance Structures ### Structure 1: Starting Structure - The positive charge is on the top nitrogen (\( N^+ \)): ``` N^+ / \ N--C C==R || / C----N ``` ### Structure 2: Shift Charge - Move the double bond from C=N to the nitrogen on the right, shifting the positive charge to the bottom nitrogen: 1. Move the lone pair from the bottom nitrogen to double bond with the bottom carbon. 2. Move the electrons from the C=N double bond to the top nitrogen to neutralize the charge. ``` N / \ N--C C==R || / C^+---N ``` - Positive charge now on the bottom nitrogen. ### Structure 3: Shift Charge Again - Move the double bond again to put the positive charge on the left nitrogen: 1. Move the lone pair from the left nitrogen to double bond with the left carbon. 2. Shift the electrons from the bottom nitrogen's double bond to this nitrogen. ``` N / \ N^+==C C==R | / C----N ``` - Positive charge on the left nitrogen. --- ## 3. Draw the Resonance Hybrid The **resonance hybrid** shows: - Partial positive charge delocalized over the three nitrogen atoms. - Dashed lines for bonds that are partially double. ``` N / \ N--C C==R || / C----N ``` - Dashed lines indicate delocalization. - Indicate partial positive (\( \delta^+ \)) on each nitrogen involved. --- ## 4. Label Final Answers ### Resonance Structures - **Structure 1**: Positive charge on the top nitrogen. - **Structure 2**: Positive charge on the bottom nitrogen. - **Structure 3**: Positive charge on the left nitrogen. ### Summary Table | Structure | Positive Charge Location | |-------------|-------------------------| | 1 | Top nitrogen | | 2 | Bottom nitrogen | | 3 | Left nitrogen | --- ## Final Answer All three resonance structures must be drawn, with the positive charge delocalized over the three nitrogen atoms. The resonance hybrid illustrates the delocalization of electrons and the partial positive charges on each nitrogen atom.