91Ó°ÊÓ

What factors determine whether a molecule or ion exhibits resonance?

What structural features do all the resonance forms of a molecule or ion have in common?

Explain why \(\mathrm{NO}_{2}\) is more likely to exhibit resonance than \(\mathrm{CO}_{2}\).

Are these two skeletal structures resonance forms: \(\mathrm{X}-\mathrm{X}-\mathrm{O}\) and \(\mathrm{X}-\mathrm{O}-\mathrm{X} ?\) Explain.

Draw Lewis structures for fulminic acid (HCNO), showing all resonance forms.

Draw Lewis structures for hydrazoic acid (HN \(_{3}\) ), showing all resonance forms.

Oxygen and nitrogen combine to form a variety of nitrogen oxides, including the following two unstable compounds, each with two nitrogen atoms per molecule: \(\mathrm{N}_{2} \mathrm{O}_{2}\) and \(\mathrm{N}_{2} \mathrm{O}_{3} .\) Draw Lewis structures for these molecules, showing all resonance forms.

Oxygen and sulfur combine to form a variety of sulfur oxides. Some are stable molecules and some, including \(\mathrm{S}_{2} \mathrm{O}_{2}\) and \(\mathrm{S}_{2} \mathrm{O}_{3},\) decompose when they are heated. Draw Lewis structures for these two compounds, showing all resonance forms.

The oxygen-oxygen distance in \(\mathrm{F}_{2} \mathrm{O}_{2}\) is about \(20 \%\) shorter than in hydrogen peroxide. a. Draw Lewis structures for both \(\mathrm{F}_{2} \mathrm{O}_{2}\) and \(\mathrm{H}_{2} \mathrm{O}_{2}\) b. It was proposed that \(\mathrm{F}_{2} \mathrm{O}_{2}\) has a resonance form of \(\left[\mathrm{FO}_{2}\right]^{+} \mathrm{F}^{-} .\) Draw a Lewis structure for this "ionic" form of \(\mathrm{F}_{2} \mathrm{O}_{2}\) and explain how the structure is consistent with the observed O-O distance.

The nitrogen-oxygen bond distance in \(\mathrm{NOF}_{3}\) is shorter than in \(\mathrm{NO}\left(\mathrm{CH}_{3}\right)_{3}\) a. Draw Lewis structures for \(\mathrm{NOF}_{3}\) and \(\mathrm{NO}\left(\mathrm{CH}_{3}\right)_{3}\) b. It was proposed that \(\mathrm{NOF}_{3}\) has a resonance form of \(\left[\mathrm{NOF}_{2}\right]^{+} \mathrm{F}^{-} .\) Draw a Lewis structure for this "ionic" form of \(\mathrm{NOF}_{3}\) and explain how the structure is consistent with the observed \(\mathrm{N}\) - \(\mathrm{O}\) distance.