Which of the following compounds or ions exhibit resonance? a. \(\mathrm{O}_{3} \quad\) d. \(\mathrm{CO}_{3}^{2-}\) b. \(\mathrm{CNO}^{-} \quad\) e. \(\mathrm{AsF}_{3}\) c. \(\mathrm{AsI}_{3}\)

For each of the given compounds and ions, draw their respective Lewis structures. Remember the rules for drawing Lewis structures: count the total number of valence electrons, place the least electronegative atom in the center, and complete the octets of the surrounding atoms. a. \(\mathrm{O}_3\): Draw a single molecule of ozone. There are 18 valence electrons, so place a double bond between one oxygen atom and the central oxygen atom, and a single bond between the central oxygen atom and the third oxygen atom. Place lone pairs on each oxygen atom to complete their octet. b. \(\mathrm{CNO}^-\): This ion has 14 valence electrons. Place carbon in the center and nitrogen and oxygen atoms on either side. Put a triple bond between carbon and nitrogen, a single bond between carbon and oxygen and 2 lone pairs on the nitrogen atom and 3 lone pairs on the oxygen atom. c. \(\mathrm{AsI}_3\): There are 26 valence electrons. Undergo the same procedure as for ozone. d. \(\mathrm{CO}_3^{2-}\): The carbonate ion has 24 valence electrons. Place carbon in the center, and arrange the oxygen atoms around it. Fill the octet for the central carbon atom by a single bond and a double bond on two other oxygen atoms accordingly. Place lone pairs on each oxygen atom. e. \(\mathrm{AsF}_3\): There are 26 valence electrons. Place a single bond between the central arsenic atom and each fluorine atom. Add 3 lone pairs on each fluorine atom and one lone pair on the central arsenic atom.

Now check each drawn Lewis structure to see if there are alternative structures with identical atom positions but differing electron pair positions: a. \(\mathrm{O}_3\): There are resonance structures as the double bond between one oxygen atom and the central oxygen atom can be replaced with a single bond, and the single bond between the third oxygen and the central oxygen atom can become a double bond, exchanging the positions of lone pairs. b. \(\mathrm{CNO}^-\): There are no resonance structures, as any change in the placement of electron pairs would result in a change of atom positions. c. \(\mathrm{AsI}_3\): No resonance structures, as there are only single bonds and no adjacent double bonds or lone pairs. d. \(\mathrm{CO}_3^{2-}\): There are resonance structures, as we can move the double bond between carbon and one oxygen atom to another oxygen atom, redistributing the positions of electron pairs, while maintaining the same atom positions. e. \(\mathrm{AsF}_3\): No resonance structures, as there are only single bonds and no adjacent double bonds or lone pairs. In conclusion: a. \(\mathrm{O}_{3}\) exhibits resonance. b. \(\mathrm{CNO}^{-}\) does not exhibit resonance. c. \(\mathrm{AsI}_{3}\) does not exhibit resonance. d. \(\mathrm{CO}_{3}^{2-}\) exhibits resonance. e. \(\mathrm{AsF}_{3}\) does not exhibit resonance.