What is the hybridization of the underlined nitrogen atom in each of the following molecules or ions? a. \(\mathrm{NO}^{+}\) b. \(\mathrm{N}_{2} \mathrm{O}_{3}\left(\mathrm{O}_{2} \mathrm{NNO}\right)\) c. \(\mathrm{NO}_{2}^{-}\) d. \(\mathrm{N}_{2}\)

(For each molecule/ion, we will determine the number of electron domains around the nitrogen atom to help us find its hybridization.) a. In \(\mathrm{NO}^{+}\), the nitrogen atom forms two bonds (one with the oxygen). Hence, it has two electron domains. b. In \(\mathrm{N}_{2} \mathrm{O}_{3}\left(\mathrm{O}_{2} \mathrm{NNO}\right)\), the central nitrogen atom forms three bonds (one with the other nitrogen atom and two with the oxygen atoms). Thus, it has three electron domains. c. In \(\mathrm{NO}_{2}^{-}\), the central nitrogen atom forms three bonds (two with the oxygen atoms) and has one lone pair of electrons. Consequently, it has four electron domains. d. In \(\mathrm{N}_{2}\), each nitrogen atom forms a triple bond with the other nitrogen atom. So, each nitrogen atom has one electron domain.

(Now that we know the number of electron domains for each nitrogen atom, we can determine their hybridization using the following rules: 2 electron domains - sp, 3 electron domains - sp2, 4 electron domains - sp3.) a. The nitrogen atom in \(\mathrm{NO}^{+}\) has two electron domains, hence it is sp hybridized. b. The central nitrogen atom in \(\mathrm{N}_{2} \mathrm{O}_{3}\left(\mathrm{O}_{2} \mathrm{NNO}\right)\) has three electron domains, hence it is sp2 hybridized. c. The nitrogen atom in \(\mathrm{NO}_{2}^{-}\) has four electron domains, hence it is sp3 hybridized. d. The nitrogen atom in \(\mathrm{N}_{2}\) has one electron domain, making it an.Exception (No hybridization). To summarize: a. \(\mathrm{NO}^{+}\): sp hybridization b. \(\mathrm{N}_{2} \mathrm{O}_{3}\left(\mathrm{O}_{2} \mathrm{NNO}\right)\): sp2 hybridization c. \(\mathrm{NO}_{2}^{-}\): sp3 hybridization d. \(\mathrm{N}_{2}\): Exception (No hybridization)