Organic Chemistry Practice Problems Cumulative General Concepts Practice Problems Solution: Write two additional resonance structures that are...

Solution: Write two additional resonance structures that are significant for the hydrocarbon anion shown below. Put in all lone pairs, multiple bonds and formal charges. Draw the curved arrows that show the delocalization of electrons. Label your two new structures as C’ & C”. Using the information on the charge distribution and your knowledge of what makes a stable contributor, indicate which (of C, C’, & C”) is/are the major-contributing and minor- contributing resonance structures that you have assigned.   Using these resonance structures, identify what the approximate charge on the oxygen atom and on the central carbon would be in the resonance hybrid. A localized charge is –1). Circle your answer below. For the oxygen atom: (a) –0.5 (b) between –0.5 and –0.33                  (c) –0.33                    (d) less than –0.33. For the center carbon: (a) –0.5 (b) between –0.5 and –0.33                   (c) –0.33                    (d) less than –0.33

Problem

Write two additional resonance structures that are significant for the hydrocarbon anion shown below. Put in all lone pairs, multiple bonds and formal charges. Draw the curved arrows that show the delocalization of electrons. Label your two new structures as C’ & C”. Using the information on the charge distribution and your knowledge of what makes a stable contributor, indicate which (of C, C’, & C”) is/are the major-contributing and minor- contributing resonance structures that you have assigned.

 

Using these resonance structures, identify what the approximate charge on the oxygen atom and on the central carbon would be in the resonance hybrid. A localized charge is –1). Circle your answer below.

For the oxygen atom:

(a) –0.5 (b) between –0.5 and –0.33                  (c) –0.33                    (d) less than –0.33.

For the center carbon:

(a) –0.5 (b) between –0.5 and –0.33                   (c) –0.33                    (d) less than –0.33